Add TOC entry for "Third-party libraries" callout section to JS docs

docs/_includes/nav/javascript.html

@@ -6,6 +6,7 @@
     <li><a href="#js-programmatic-api">Programmatic API</a></li>
     <li><a href="#js-noconflict">No conflict</a></li>
     <li><a href="#js-events">Events</a></li>
+    <li><a href="#callout-third-party-libs">Third-party libraries</a></li>
   </ul>
 </li>
 <li><a href="#transitions">Transitions</a></li>