Remove .html extension from links

chrome/common/extensions/docs/templates/intros/permissions.html

 <h2 id="howto"> Implementing optional permissions </h2>
 
 <h3 id="types">
 Step 1: Decide which permissions are required and which are optional
 </h3>
 
 <p>
 An extension can declare both required and optional permissions. In general, you should:
 <ul>
   <li>Use required permissions when they are needed for your extension’s basic functionality.</li>
@@ skipping 18 matching lines @@
       Extensions run with fewer permissions since users only enable permissions that are needed.</li>
   <li><strong>Better information for users:</strong>
       An extension can explain why it needs a particular permission when the user enables the relevant feature.</li>
   <li><strong>Easier upgrades:</strong>
       When you upgrade your extension, Chrome will not disable it for your users if the upgrade adds optional rather than required permissions.</li>
 </ul>
 </p>
 
 <h3 id="manifest"> Step 2: Declare optional permissions in the manifest </h3>
 <p>
-  Declare optional permissions in your <a href="manifest.html">extension
+  Declare optional permissions in your <a href="manifest">extension
   manifest</a> with the <code>optional_permissions</code> key, using the
-  same format as the <a href="declare_permissions.html#manifest">permissions</a>
+  same format as the <a href="declare_permissions#manifest">permissions</a>
   field:
 </p>
 
 <pre data-filename="manifest.json">
 {
   "name": "My extension",
   ...
   <b>"optional_permissions": [ "tabs", "http://www.google.com/" ],</b>
   ...
 }
 </pre>
 
 <p>
 You can specify any of the following as optional
-<a href="declare_permissions.html">permissions</a>:
+<a href="declare_permissions">permissions</a>:
 <ul>
   <li><i>host permissions</i></li>
   <li>background</li>
   <li>bookmarks</li>
   <li>clipboardRead</li>
   <li>clipboardWrite</li>
   <li>contentSettings</li>
   <li>contextMenus</li>
   <li>cookies</li>
   <li>debugger</li>
@@ skipping 34 matching lines @@
     } else {
       doSomethingElse();
     }
   });
 });
 </pre>
 </p>
 
 <p>
   Chrome prompts the user if adding the permissions results in different
-  <a href="permission_warnings.html">warning messages</a> than the user has
+  <a href="permission_warnings">warning messages</a> than the user has
   already seen and accepted. For example, the previous code might result in
   a prompt like this:
 </p>
 
 <p style="text-align: center">
   <img src="{{static}}/images/perms-optional.png"
        alt="example permission confirmation prompt"
        width="490" height="193">
 </p>
 
@@ skipping 30 matching lines @@
   origins: ['http://www.google.com/']
 }, function(removed) {
   if (removed) {
     // The permissions have been removed.
   } else {
     // The permissions have not been removed (e.g., you tried to remove
     // required permissions).
   }
 });
 </pre>