Updates readme.txt details

git-svn-id: https://plugins.svn.wordpress.org/prismatic/trunk@1974532 b8457f37-d9ea-0310-8a92-e5e31aec5664

readme.txt

@@ -318,12 +318,11 @@ So for example, to specify a code block as C++, you would write:
 	
 	Multi-line: <pre><code class="language-cpp">...</code></pre>
 	
-	Alternate: <pre class="language-cpp">
-	                <code>...</code>
-	           </pre>
+	Alternate: <pre class="language-cpp"><code class="optional">...</code></pre>
 
-To disable Prism.js syntax highlighting for any snippet, simply omit the language class.
+Note: in the previous example, ignore the `class="optional"` added to the `<code>` tag (for the "Alternate" syntax); it is used to prevent markdown from mangling the code example.
 
+To disable Prism.js syntax highlighting for any snippet, simply omit the language class. 
 
 _I'm glad to add more languages, [make a suggestion](https://perishablepress.com/contact/)_
 
@@ -389,9 +388,9 @@ So for example, to specify a code block as C++, you would write:
 	
 	Multi-line: <pre><code class="language-cpp">...</code></pre>
 	
-	Alternate: <pre class="language-cpp">
-	                <code>...</code>
-	           </pre>
+	Alternate: <pre class="language-cpp"><code class="optional">...</code></pre>
+
+Note: in the previous example, ignore the `class="optional"` added to the `<code>` tag (for the "Alternate" syntax); it is used to prevent markdown from mangling the code example.
 
 To disable Highlight.js syntax highlighting for any code block, add a class of `nohighlight`, like so: