chore: import upstream snapshot with attribution

docs/expressions/comments.html

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+<h4>Comments</h4>
+<p>Comments can be used to explain <b>Shell</b> code, and to make it more readable. It can also be used to prevent execution <b>Shell</b> code. Comments can be singled-lined or multi-lined.</p>
+<div id="single-line">
+	<h5>Single-line Comments</h5>
+	<p>
+		Single-line comments start with two forward slashes (<code>//</code>).<br>
+		Any text between <code>//</code> and the end of the line is ignored (will not be executed).
+	</p>
+	<p>This example uses a single-line comment before a line of code:</p>
+	<pre><code class="lang-shell">dynamic 
+{
+	// This is a comment
+	item(title='Hello World!')
+	
+	//item(title='Hello World!')
+}</code></pre>
+
+	<p>This example uses a single-line comment at the end of a line of code:</p>
+	<pre><code class="lang-shell">dynamic 
+{
+    item(title='Hello World!') // This is a comment
+}</code></pre>
+</div>
+<br>
+<div id="multi-line">
+	<h5>Multi-line Comments</h5>
+	<p>
+		Multi-line comments start with <code>/*</code> and ends with <code>*/</code>.<br>
+		Any text between <code>/*</code> and <code>*/</code> will be ignored.
+	</p>
+<pre><code class="lang-shell">dynamic
+{
+	item(title='Hello,/* multiple-lines comment inside */ world')
+	
+	/*
+	item(title='test item 1')
+	item(title='test item 2')
+	*/
+}</code></pre>
+	<p>
+		Single or multi-line comments?<br>
+		It is up to you which you want to use. Normally, we use <code>//</code> for short comments, and <code>/* */</code> for longer.
+	</p>
+</div>