Remove .html extension from links

chrome/common/extensions/docs/templates/articles/manifest/url_handlers.html

 <h1 id="url_handlers">url_handlers</h1>
 
 <p>
-Used by <a href="../app_lifecycle.html#eventpage">packaged apps</a>
+Used by <a href="../app_lifecycle#eventpage">packaged apps</a>
 to specify URL patterns the app wants to intercept and handle. An app can
 define multiple URL handlers under this manifest entry, each having an identifier,
 a URL pattern, and a title.
 Here's an example of how to specify <code>url_handlers</code>:
 </p>
 
 <pre data-filename="manifest.json">
 "url_handlers": {
   "view_foo_presentation": {
     "matches": [
@@ skipping 25 matching lines @@
 </p>
 <p>
 This automatically means that at least a complete domain should always be
 specified for all the patterns under <code>matches</code> (otherwise ownership
 cannot be verified).
 </p>
 <p>
 Upon successful registration and installation, an app will be launched for all
 matching navigations inside browser tabs as well as other apps. The app will
 receive a new kind of the
-<a href="../app_runtime.html#event-onLaunched">app.runtime.onLaunched</a>
+<a href="../app_runtime#event-onLaunched">app.runtime.onLaunched</a>
 event, with the launchData
 object containing the matched handler's identifier (such as "view_foo_presentation"
 above), the URL being navigated to, and the referrer's URL.
 </p>
 <p>
 The <code>title</code> field is reserved for future use in all relevant UI elements.
 It should describe the action that the app performs when launched with this type
 of URL handler.
 </p>