Remove .html extension from links

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

 <h2 id="manifest">Manifest</h2>
 <p>You must declare the "proxy" permission
-in the <a href="manifest.html">extension manifest</a>
+in the <a href="manifest">extension manifest</a>
 to use the proxy settings API.
 For example:</p>
 <pre data-filename="manifest.json">
 {
   "name": "My extension",
   ...
   <b>"permissions": [
     "proxy"
   ]</b>,
   ...
@@ skipping 154 matching lines @@
 </dl>
 
 
 <h2 id="overview-examples">Examples</h2>
 
 <p>
 The following code sets a SOCKS 5 proxy for HTTP connections to all servers but
 foobar.com and uses direct connections for all other protocols. The settings
 apply to regular and incognito windows, as incognito windows inherit settings
 from regular windows. Please also consult the <a
-  href="types.html#ChromeSetting">Types API</a> documentation.
+  href="types#ChromeSetting">Types API</a> documentation.
 </p>
 
 <pre>
 var config = {
   mode: "fixed_servers",
   rules: {
     proxyForHttp: {
       scheme: "socks5",
       host: "1.2.3.4"
     },
@@ skipping 21 matching lines @@
   }
 };
 chrome.proxy.settings.set(
     {value: config, scope: 'regular'},
     function() {});
 </pre>
 
 <p>
 The next snippet queries the currently effective proxy settings. The effective
 proxy settings can be determined by another extension or by a policy. See the <a
-  href="types.html#ChromeSetting">Types API</a> documentation for details.
+  href="types#ChromeSetting">Types API</a> documentation for details.
 </p>
 
 <pre>
 chrome.proxy.settings.get(
     {'incognito': false},
     function(config) {console.log(JSON.stringify(config));});
 </pre>
 
 <p>
 Note that the <code>value</code> object passed to <code>set()</code> is not
 identical to the <code>value</code> object passed to callback function of
 <code>get()</code>. The latter will contain a
 <code>rules.proxyForHttp.port</code> element.
 </p>