Add missing about link

Author: steveck-chung

project.html

@@ -63,6 +63,7 @@
           <li><a href="projects.html">Projects</a></li>
           <!-- <li><a href="getting-started.html">Document</a></li> -->
           <li><a href="http://blog.sensorweb.io">Blog</a></li>
+          <li><a href="about.html">About</a></li>
           <li id="app-download-li" class="hide"><a class="modal-trigger" href="#app-dl-modal">Download App</a></li>
           <!-- <li><a href="user-detail.html">Log In</a></li> -->
         </ul>