Remove summary and seoSummary classes from JS docs

[wbamberg]

Fixes #4083.

This removes all uses of summary or seoSummary in cases where those classes actually do something. In most cases the classes are selecting the first portion of the first paragraph, and in most of those cases I've just removed them so we will use the whole first paragraph. I think this is OK, none of them are very long, and in the other 800-odd pages where we are not using these classes there are many similarly long paragraphs: https://gist.github.com/wbamberg/3e6f1d6d995189596647a7342c3f0d9e.

In a few places I've made more extensive changes, for wording, or to try to make the summary more coherent.

[github-actions]

Preview URLs

• https://pr4085.content.dev.mdn.mozit.cloud/en-US/docs/Web/JavaScript
• https://pr4085.content.dev.mdn.mozit.cloud/en-US/docs/Web/JavaScript/EventLoop
• https://pr4085.content.dev.mdn.mozit.cloud/en-US/docs/Web/JavaScript/Guide/Numbers_and_dates
• https://pr4085.content.dev.mdn.mozit.cloud/en-US/docs/Web/JavaScript/Guide/Iterators_and_Generators
• https://pr4085.content.dev.mdn.mozit.cloud/en-US/docs/Web/JavaScript/Typed_arrays
• https://pr4085.content.dev.mdn.mozit.cloud/en-US/docs/Web/JavaScript/Reference/Classes/static
• https://pr4085.content.dev.mdn.mozit.cloud/en-US/docs/Web/JavaScript/Reference/Operators/Optional_chaining
• https://pr4085.content.dev.mdn.mozit.cloud/en-US/docs/Web/JavaScript/Reference/Operators/Conditional_Operator
• https://pr4085.content.dev.mdn.mozit.cloud/en-US/docs/Web/JavaScript/Reference/Global_Objects/RangeError
• https://pr4085.content.dev.mdn.mozit.cloud/en-US/docs/Web/JavaScript/Reference/Global_Objects/RangeError/RangeError
• https://pr4085.content.dev.mdn.mozit.cloud/en-US/docs/Web/JavaScript/Reference/Global_Objects/Reflect/setPrototypeOf
• https://pr4085.content.dev.mdn.mozit.cloud/en-US/docs/Web/JavaScript/Reference/Global_Objects/Reflect/preventExtensions
• https://pr4085.content.dev.mdn.mozit.cloud/en-US/docs/Web/JavaScript/Reference/Global_Objects/Math/abs
• https://pr4085.content.dev.mdn.mozit.cloud/en-US/docs/Web/JavaScript/Reference/Global_Objects/Math/cos
• https://pr4085.content.dev.mdn.mozit.cloud/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/replace
• https://pr4085.content.dev.mdn.mozit.cloud/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/padStart
• https://pr4085.content.dev.mdn.mozit.cloud/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/raw
• https://pr4085.content.dev.mdn.mozit.cloud/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/replaceAll
• https://pr4085.content.dev.mdn.mozit.cloud/en-US/docs/Web/JavaScript/Reference/Global_Objects/Map
• https://pr4085.content.dev.mdn.mozit.cloud/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date
• https://pr4085.content.dev.mdn.mozit.cloud/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date/getDay
• https://pr4085.content.dev.mdn.mozit.cloud/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date/Date
• https://pr4085.content.dev.mdn.mozit.cloud/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number/isFinite
• https://pr4085.content.dev.mdn.mozit.cloud/en-US/docs/Web/JavaScript/Reference/Statements/import
• https://pr4085.content.dev.mdn.mozit.cloud/en-US/docs/Web/JavaScript/Reference/Statements/async_function

Flaws

URL: /en-US/docs/Web/JavaScript
Title: JavaScript
on GitHub

No flaws! 🎉

---

URL: /en-US/docs/Web/JavaScript/EventLoop
Title: Concurrency model and the event loop
on GitHub

No flaws! 🎉

---

URL: /en-US/docs/Web/JavaScript/Guide/Numbers_and_dates
Title: Numbers and dates
on GitHub

No flaws! 🎉

---

URL: /en-US/docs/Web/JavaScript/Guide/Iterators_and_Generators
Title: Iterators and generators
on GitHub

No flaws! 🎉

---

URL: /en-US/docs/Web/JavaScript/Typed_arrays
Title: JavaScript typed arrays
on GitHub
Flaw count: 1

• broken_links:
  • Can't resolve /en-US/docs/Code_snippets/StringView

---

URL: /en-US/docs/Web/JavaScript/Reference/Classes/static
Title: static
on GitHub

No flaws! 🎉

---

URL: /en-US/docs/Web/JavaScript/Reference/Operators/Optional_chaining
Title: Optional chaining (?.)
on GitHub
Flaw count: 2

• broken_links:
  • Anchor not lowercase
  • Anchor not lowercase

---

URL: /en-US/docs/Web/JavaScript/Reference/Operators/Conditional_Operator
Title: Conditional (ternary) operator
on GitHub

No flaws! 🎉

---

URL: /en-US/docs/Web/JavaScript/Reference/Global_Objects/RangeError
Title: RangeError
on GitHub

No flaws! 🎉

---

URL: /en-US/docs/Web/JavaScript/Reference/Global_Objects/RangeError/RangeError
Title: RangeError() constructor
on GitHub
Flaw count: 1

• bad_pre_tags:
  • <pre><code>CODE can be just <pre>CODE

---

URL: /en-US/docs/Web/JavaScript/Reference/Global_Objects/Reflect/setPrototypeOf
Title: Reflect.setPrototypeOf()
on GitHub

No flaws! 🎉

---

URL: /en-US/docs/Web/JavaScript/Reference/Global_Objects/Reflect/preventExtensions
Title: Reflect.preventExtensions()
on GitHub
Flaw count: 1

• broken_links:
  • Anchor not lowercase

---

URL: /en-US/docs/Web/JavaScript/Reference/Global_Objects/Math/abs
Title: Math.abs()
on GitHub

No flaws! 🎉

---

URL: /en-US/docs/Web/JavaScript/Reference/Global_Objects/Math/cos
Title: Math.cos()
on GitHub

No flaws! 🎉

---

URL: /en-US/docs/Web/JavaScript/Reference/Global_Objects/String/replace
Title: String.prototype.replace()
on GitHub
Flaw count: 3

• broken_links:
  • Anchor not lowercase
  • Anchor not lowercase
  • Anchor not lowercase

---

URL: /en-US/docs/Web/JavaScript/Reference/Global_Objects/String/padStart
Title: String.prototype.padStart()
on GitHub

No flaws! 🎉

---

URL: /en-US/docs/Web/JavaScript/Reference/Global_Objects/String/raw
Title: String.raw()
on GitHub
Flaw count: 4

• broken_links:
  • Can't resolve /en-US/docs/Web/JavaScript/Reference/template_strings
  • Can't resolve /en-US/docs/Web/JavaScript/Reference/template_strings#Tagged_template_literals
  • Can't resolve /en-US/docs/Web/JavaScript/Reference/template_strings
• bad_pre_tags:
  • <pre><code>CODE can be just <pre>CODE

---

URL: /en-US/docs/Web/JavaScript/Reference/Global_Objects/String/replaceAll
Title: String.prototype.replaceAll()
on GitHub
Flaw count: 2

• broken_links:
  • Anchor not lowercase
  • Anchor not lowercase

---

URL: /en-US/docs/Web/JavaScript/Reference/Global_Objects/Map
Title: Map
on GitHub
Flaw count: 3

• broken_links:
  • Anchor not lowercase
  • Can't resolve /en-US/docs/Web/JavaScript/Guide/iterable
  • Anchor not lowercase

---

URL: /en-US/docs/Web/JavaScript/Reference/Global_Objects/Date
Title: Date
on GitHub
Flaw count: 1

• macros:
  • /en-US/docs/Web/JavaScript/Reference/Global_Objects/Date/toLocaleFormat does not exist

---

URL: /en-US/docs/Web/JavaScript/Reference/Global_Objects/Date/getDay
Title: Date.prototype.getDay()
on GitHub
Flaw count: 1

• macros:
  • /en-US/docs/Web/JavaScript/Reference/Global_Objects/DateTimeFormat redirects to /en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/DateTimeFormat

---

URL: /en-US/docs/Web/JavaScript/Reference/Global_Objects/Date/Date
Title: Date() constructor
on GitHub
Flaw count: 2

• macros:
  • /en-US/docs/Web/JavaScript/Reference/new does not exist
• broken_links:
  • Anchor not lowercase

---

URL: /en-US/docs/Web/JavaScript/Reference/Global_Objects/Number/isFinite
Title: Number.isFinite()
on GitHub

No flaws! 🎉

---

URL: /en-US/docs/Web/JavaScript/Reference/Statements/import
Title: import
on GitHub

No flaws! 🎉

---

URL: /en-US/docs/Web/JavaScript/Reference/Statements/async_function
Title: async function
on GitHub

No flaws! 🎉

External URLs

URL: /en-US/docs/Web/JavaScript
Title: JavaScript
on GitHub

• http://www.adobe.com/devnet/acrobat/javascript.html (1 time)
• https://codepen.io/ (1 time)
• https://couchdb.apache.org/ (1 time)
• https://en.wikipedia.org/wiki/JavaScript (1 time)
• https://en.wikipedia.org/wiki/Java_(programming_language) (1 time)
• https://en.wikipedia.org/wiki/Just-in-time_compilation (1 time)
• https://jsbin.com/ (1 time)
• https://jsfiddle.net/ (1 time)
• https://kangax.github.io/compat-table/es5/ (1 time)
• https://learnjavascript.online/ (1 time)
• https://plnkr.co/ (1 time)
• https://runjs.app/ (1 time)
• https://stackblitz.com/ (1 time)
• https://stackoverflow.com/questions/tagged/javascript (1 time)
• https://tc39.github.io/ecma262/ (1 time)
• https://togetherjs.com/ (1 time)
• https://www.ecma-international.org (1 time)

---

URL: /en-US/docs/Web/JavaScript/EventLoop
Title: Concurrency model and the event loop
on GitHub

• http://stackoverflow.com/questions/2734025/is-javascript-guaranteed-to-be-single-threaded/2734311 (1 time)
• https://html.spec.whatwg.org/multipage/webappapis.html (1 time)
• https://nodejs.org/en/docs/guides/event-loop-timers-and-nexttick/ (1 time)

---

URL: /en-US/docs/Web/JavaScript/Guide/Numbers_and_dates
Title: Numbers and dates
on GitHub

• https://en.wikipedia.org/wiki/Double-precision_floating-point_format (1 time)

---

URL: /en-US/docs/Web/JavaScript/Guide/Iterators_and_Generators
Title: Iterators and generators
on GitHub

No external URLs

URL: /en-US/docs/Web/JavaScript/Typed_arrays
Title: JavaScript typed arrays
on GitHub

• http://www.html5rocks.com/en/tutorials/webgl/typed_arrays (1 time)
• https://en.wikipedia.org/wiki/Data_structure_alignment (1 time)
• https://hacks.mozilla.org/2011/12/faster-canvas-pixel-manipulation-with-typed-arrays (1 time)
• https://tc39.es/ecma262/ (1 time)

---

URL: /en-US/docs/Web/JavaScript/Reference/Classes/static
Title: static
on GitHub

• https://tc39.es/ecma262/ (1 time)

---

URL: /en-US/docs/Web/JavaScript/Reference/Operators/Optional_chaining
Title: Optional chaining (?.)
on GitHub

• https://tc39.es/ecma262/ (1 time)

---

URL: /en-US/docs/Web/JavaScript/Reference/Operators/Conditional_Operator
Title: Conditional (ternary) operator
on GitHub

• https://tc39.es/ecma262/ (1 time)

---

URL: /en-US/docs/Web/JavaScript/Reference/Global_Objects/RangeError
Title: RangeError
on GitHub

• https://tc39.es/ecma262/ (1 time)

---

URL: /en-US/docs/Web/JavaScript/Reference/Global_Objects/RangeError/RangeError
Title: RangeError() constructor
on GitHub

• https://tc39.es/ecma262/ (1 time)

---

URL: /en-US/docs/Web/JavaScript/Reference/Global_Objects/Reflect/setPrototypeOf
Title: Reflect.setPrototypeOf()
on GitHub

• https://tc39.es/ecma262/ (1 time)

---

URL: /en-US/docs/Web/JavaScript/Reference/Global_Objects/Reflect/preventExtensions
Title: Reflect.preventExtensions()
on GitHub

• https://tc39.es/ecma262/ (1 time)

---

URL: /en-US/docs/Web/JavaScript/Reference/Global_Objects/Math/abs
Title: Math.abs()
on GitHub

• https://tc39.es/ecma262/ (1 time)

---

URL: /en-US/docs/Web/JavaScript/Reference/Global_Objects/Math/cos
Title: Math.cos()
on GitHub

• https://en.wikipedia.org/wiki/Cosine (1 time)
• https://en.wikipedia.org/wiki/Radians (1 time)
• https://tc39.es/ecma262/ (1 time)

---

URL: /en-US/docs/Web/JavaScript/Reference/Global_Objects/String/replace
Title: String.prototype.replace()
on GitHub

• https://tc39.es/ecma262/ (1 time)

---

URL: /en-US/docs/Web/JavaScript/Reference/Global_Objects/String/padStart
Title: String.prototype.padStart()
on GitHub

• https://github.com/behnammodi/polyfill/blob/master/string.polyfill.js (1 time)
• https://tc39.es/ecma262/ (1 time)

---

URL: /en-US/docs/Web/JavaScript/Reference/Global_Objects/String/raw
Title: String.raw()
on GitHub

• https://bugs.chromium.org/p/v8/issues/detail?id=5016 (1 time)
• https://tc39.es/ecma262/ (1 time)

---

URL: /en-US/docs/Web/JavaScript/Reference/Global_Objects/String/replaceAll
Title: String.prototype.replaceAll()
on GitHub

• https://tc39.es/ecma262/ (1 time)

---

URL: /en-US/docs/Web/JavaScript/Reference/Global_Objects/Map
Title: Map
on GitHub

• https://tc39.es/ecma262/ (3 times)

---

URL: /en-US/docs/Web/JavaScript/Reference/Global_Objects/Date
Title: Date
on GitHub

• https://blogs.igalia.com/compilers/2020/06/23/dates-and-times-in-javascript/ (1 time)
• https://tc39.es/ecma262/ (1 time)
• https://tc39.es/proposal-temporal/docs/index.html (1 time)

---

URL: /en-US/docs/Web/JavaScript/Reference/Global_Objects/Date/getDay
Title: Date.prototype.getDay()
on GitHub

• https://tc39.es/ecma262/ (1 time)

---

URL: /en-US/docs/Web/JavaScript/Reference/Global_Objects/Date/Date
Title: Date() constructor
on GitHub

• http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap04.html (1 time)
• https://datatracker.ietf.org/doc/html/rfc2822 (2 times)
• https://tc39.es/ecma262/ (1 time)
• https://www.ecma-international.org/ecma-262/11.0/ (1 time)

---

URL: /en-US/docs/Web/JavaScript/Reference/Global_Objects/Number/isFinite
Title: Number.isFinite()
on GitHub

• https://tc39.es/ecma262/ (1 time)

---

URL: /en-US/docs/Web/JavaScript/Reference/Statements/import
Title: import
on GitHub

• http://exploringjs.com/es6/ch_modules.html (1 time)
• https://blogs.windows.com/msedgedev/2016/05/17/es6-modules-and-beyond/ (1 time)
• https://hacks.mozilla.org/2015/08/es6-in-depth-modules/ (1 time)
• https://hacks.mozilla.org/2018/03/es-modules-a-cartoon-deep-dive/ (1 time)
• https://javascript.info/import-export (1 time)
• https://tc39.es/ecma262/ (2 times)

---

URL: /en-US/docs/Web/JavaScript/Reference/Statements/async_function
Title: async function
on GitHub

• http://innolitics.com/10x/javascript-decorators-for-promise-returning-functions/ (1 time)
• https://tc39.es/ecma262/ (1 time)

[Elchi3]

Looks good to me!
I think it is okay to remove the MathML as well. It is probably enough to explain the things in English and it avoids the compat problems with displaying MathML well enough across browsers.