docs(index): make menu links relative

Before the Develop drop down menu items were hard coded with an absolute url,
which meant that they did not work correctly on local or ci server builds.

Author: siddii

docs/src/templates/index.html

@@ -142,9 +142,9 @@
                 <i class="icon-book icon-white"></i> Develop <b class="caret"></b>
               </a>
               <ul class="dropdown-menu">
-                <li><a href="http://docs.angularjs.org/tutorial">Tutorial</a></li>
-                <li><a href="http://docs.angularjs.org/guide/">Developer Guide</a></li>
-                <li><a href="http://docs.angularjs.org/api/">API Reference</a></li>
+                <li><a href="./tutorial/">Tutorial</a></li>
+                <li><a href="./guide/">Developer Guide</a></li>
+                <li><a href="./api/">API Reference</a></li>
                 <li><a href="http://docs.angularjs.org/misc/contribute">Contribute</a></li>
                 <li><a href="http://code.angularjs.org/">Download</a></li>
               </ul>