docs(readme.md): update readme

packages/lit-override/README.md

@@ -76,14 +76,6 @@ export class ChildComponent extends LitElement {
     return html`${templateContentWithFallback({ fallback: html`<p>Default markup</p>`, id: this.templateId })}`;
   }
 }
-
-customElements.define('child-component', ChildComponent);
-
-declare global {
-  interface HTMLElementTagNameMap {
-    'child-component': ChildComponent;
-  }
-}
 ```
 
 Set `templateId` on `child-component` to point to the template from which to add styles and markup overrides from:
@@ -158,8 +150,6 @@ render() {
 
 **Note**: Go to the `lit-override` project via [`apps/lit-override`](../../apps/lit-override) to see more examples.
 
-For a similar native web component implementation, check out [this article](https://css-tricks.com/encapsulating-style-and-structure-with-shadow-dom/#aa-the-best-of-both-worlds) and associated [codepen](https://codepen.io/calebdwilliams/pen/rROadR).
-
 ## Background
 
 When building out a design library, I came across situations where I needed a parent component/app to override child component styles and markup. Use cases included rendering different combinations of `p` tags, `div` tags, images, and other basic elements. Implementing, however, wouldn't be easy for many reasons. Dealing with component `shadowroot`s makes overriding particularly difficult. There are also reliability issues with race conditions when applying overrides to childen components.