Remove .html extension from links

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

 <p>
-See <a href="devtools.html">DevTools APIs summary</a> for
+See <a href="devtools">DevTools APIs summary</a> for
 general introduction to using Developer Tools APIs.
 </p>
 
 <h2 id="overview">Overview</h2>
 
 <p>
 Each extension panel and sidebar is displayed as a separate HTML page. All
 extension pages displayed in the Developer Tools window have access to all
 modules in <code>chrome.devtools</code> API, as well as to
-<a href="extension.html">chrome.extension</a> API. Other extension APIs are not
+<a href="extension">chrome.extension</a> API. Other extension APIs are not
 available to the pages within Developer Tools window, but you may invoke them
 by sending a request to the background page of your extension, similarly to how
-it's done in the <a href="overview.html#contentScripts">content scripts</a>.
+it's done in the <a href="overview#contentScripts">content scripts</a>.
 </p><p>
 You can use the <code>$(ref:devtools.panels.setOpenResourceHandler)
 </code> method to install a
 callback function that handles user requests to open a resource (typically,
 a click on a resource link in the Developer Tools window). At most one of the
 installed handlers gets called; users can specify (using the Developer Tools
 Settings dialog) either the default behavior or an extension to handle resource
 open requests. If an extension calls <code>setOpenResourceHandler()</code>
 multiple times, only the last handler is retained.
 </p>
@@ skipping 23 matching lines @@
 Developer Tools window:
 
 <img src="{{static}}/images/devtools-panels.png"
      style="margin-left: 20px"
      width="686" height="289"
      alt="Extension icon panel on DevTools toolbar" />
 </p>
 
 <p>
 You can find examples that use this API in
-<a href="samples.html#chrome-query">Samples</a>.
+<a href="samples#chrome-query">Samples</a>.
 </p>