Add a small syntax cheatsheet

docs/grammar.html

@@ -259,6 +259,7 @@ <h1><a href="/">nearley<span style="color: #559;">.js</span><span id="version">2
             <a href="#" class="page-title-active">Writing a parser</a>
             <ul>
                 <li class="page-heading"><a href="#vocabulary">Vocabulary</a>
+                <li class="page-heading"><a href="#matching-rules">Matching Rules</a>
                 <li class="page-heading"><a href="#postprocessors">Postprocessors</a>
                 <li class="page-heading"><a href="#more-syntax-tips-and-tricks">More syntax: tips and tricks</a>
                 <li class="page-heading"><a href="#macros">Macros</a>
@@ -319,6 +320,22 @@ <h3 id="vocabulary">Vocabulary</h3>
 following nonterminal matches zero or more <code>cow</code>s in a row, such as
 <code>cowcowcow</code>:</p>
 <pre><code class="language-ne">a -&gt; null | a &quot;cow&quot;</code></pre>
+<h3 id="matching-rules">Matching Rules</h3>
+<p>Syntax for matching input if you’re not using a tokenizer.</p>
+<ul>
+<li><code>&quot;if&quot;</code> - match <code>if</code> literally</li>
+<li><code>&quot;if&quot;i</code> - match <code>if</code> case-insensitive (1)</li>
+<li><code>.</code> - match any symbol except newline</li>
+<li><code>[^]</code> - match anything including newline</li>
+<li><code>[a-zA-Z]</code> - match symbols in range (2)</li>
+<li><code>[^a-zA-Z]</code> - match symbols not in range</li>
+<li><code>:+</code> - match previous construction one or more time</li>
+<li><code>:*</code> - match zero times or more</li>
+<li><code>:?</code> - zero time or one time</li>
+</ul>
+<p>(1) <code>i</code> suffix will <em>not</em> work with a lexer if you’re using one. Your lexer
+should use the <code>i</code> flag in its regexes instead.</p>
+<p>(2) RegExp charsets will not work with <a href="tokenizers">tokenizer</a>.</p>
 <h3 id="postprocessors">Postprocessors</h3>
 <p>By default, nearley wraps everything matched by a rule into an array. For
 example, when <code>rule -&gt; &quot;tick&quot; &quot;tock&quot;</code> matches the string <code>&quot;ticktock&quot;</code>, it
@@ -395,16 +412,6 @@ <h4 id="comments">Comments</h4>
 <p>Comments are marked with ‘#’. Everything from <code>#</code> to the end of a line is
 ignored:</p>
 <pre><code class="language-ne">expression -&gt; number &quot;+&quot; number # sum of two numbers</code></pre>
-<h4 id="charsets">Charsets</h4>
-<p>You can use valid RegExp charsets in a rule (unless you’re using a
-<a href="tokenizers">tokenizer</a>):</p>
-<pre><code>not_a_letter -&gt; [^a-zA-Z]</code></pre><p>The <code>.</code> character can be used to represent any character.</p>
-<h4 id="case-insensitive-string-literals">Case-insensitive string literals</h4>
-<p>You can create case-insensitive string literals by adding an <code>i</code> after the
-string literal:</p>
-<pre><code>cow -&gt; &quot;cow&quot;i # matches CoW, COW, and so on.</code></pre><p>Note that if you are using a lexer, your lexer should use the <code>i</code> flag in its
-regexes instead. That is, if you are using a lexer, you should <em>not</em> use the
-<code>i</code> suffix in nearley.</p>
 <h4 id="ebnf">EBNF</h4>
 <p>nearley supports the <code>*</code>, <code>?</code>, and <code>+</code> operators from
 <a href="https://en.wikipedia.org/wiki/Extended_Backus%E2%80%93Naur_form">EBNF</a> as shown:</p>

docs/md/grammar.md

@@ -62,6 +62,26 @@ following nonterminal matches zero or more `cow`s in a row, such as
 a -> null | a "cow"
 ```
 
+### Matching Rules
+
+Syntax for matching input if you're not using a tokenizer.
+
+  * `"if"` - match `if` literally
+  * `"if"i` - match `if` case-insensitive (1)
+  * `.` - match any symbol except newline
+  * `[^]` - match anything including newline
+  * `[a-zA-Z]` - match symbols in range (2)
+  * `[^a-zA-Z]` - match symbols not in range
+  * `:+` - match previous construction one or more time
+  * `:*` - match zero times or more
+  * `:?` - zero time or one time
+
+(1) `i` suffix will *not* work with a lexer if you're using one. Your lexer
+should use the `i` flag in its regexes instead.
+
+(2) RegExp charsets will not work with [tokenizer](tokenizers).
+
+
 ### Postprocessors
 
 By default, nearley wraps everything matched by a rule into an array. For
@@ -154,26 +174,6 @@ ignored:
 expression -> number "+" number # sum of two numbers
 ```
 
-#### Charsets
-
-You can use valid RegExp charsets in a rule (unless you're using a
-[tokenizer](tokenizers)):
-
-    not_a_letter -> [^a-zA-Z]
-
-The `.` character can be used to represent any character.
-
-#### Case-insensitive string literals
-
-You can create case-insensitive string literals by adding an `i` after the
-string literal:
-
-    cow -> "cow"i # matches CoW, COW, and so on.
-
-Note that if you are using a lexer, your lexer should use the `i` flag in its
-regexes instead. That is, if you are using a lexer, you should *not* use the
-`i` suffix in nearley.
-
 #### EBNF
 
 nearley supports the `*`, `?`, and `+` operators from