Dynamically generate a heading for Extension Docs API pages

chrome/common/extensions/docs/templates/articles/whats_new.html

 <h1>What's New in Extensions?</h1>
 <!--  -->
 
 <p>
 This page lists the API and manifest changes
 made in recent releases.
 </p>
 
 <h2 id="26"> Google Chrome 26 </h2>
 
@@ skipping 475 matching lines @@
     <li>The $ref:windows.create
       method can now take a <code>focused</code> value.
       Previously, all new windows had the keyboard focus;
       now you can create windows without interrupting the user's typing.
     <li>If the manifest specifies "experimental" permission,
       your extension can specify "panel" as the value of
       the <code>type</code> field in
       the $ref:windows.create
       method
       or the $ref:windows.Window type.
-    <li>The $ref:cookies.onChanged
+ <!--   <li>The $ref:cookies.onChanged

[cduvall, 2013/03/21 18:43:53]

Fix this, and uncomment.

[epeterson, 2013/03/25 19:35:11]

Done.

       event of <code>chrome.cookies</code>
-      now has a <code>cause</code> parameter.
+      now has a <code>cause</code> parameter. -->
     <li>The <code>chrome.contextMenus</code>
       $ref:contextMenus.create and
       $ref:contextMenus.update
       methods now let you specify a context value of "frame".
   </ul>
 
 <h2 id="11"> Google Chrome 11 </h2>
 
 <h4> Changes to existing APIs </h4>
   <ul>
@@ skipping 134 matching lines @@
 <h4> Manifest changes </h4>
   <ul>
     <li>The <a href="manifest.html#geolocation">geolocation</a> permission
       gives an extension access to the user's physical location.
     <li><a href="match_patterns.html">Match patterns</a> can now select all
       schemes or all URLs.
     <li>Access to file:/// URLs no longer triggers the "access to your machine"
       security warning, but now requires user opt-in from the extensions
       management page.
   </ul>