Add link to API communication example from docs, as it's confirmed to…

… be working

docs/index.html

@@ -17,7 +17,8 @@ <h1>LocAR.js examples</h1>
 <ol>
 <li><a href='01-helloworld/index.html'>Hello World</a>: Display a red cube just to the north of a fake GPS location. Can be tested on a desktop or laptop.</li>
 <li><a href='02-gps-and-sensors/index.html'>GPS and Sensors</a>: Requires a mobile device wih GPS and sensors. Demonstrates use of the GPS and the device sensors to show real AR. Gets your initial location and displays four coloured boxes to the north (red), south (yellow), west (blue) and east (green) of your initial location. Can be used as a test to check whether your device sensors are accurate; if the red box does not appear to the North, your device sensors may be mis-calibrated.</li>
-<li><a href='03-ar-objects/index.html'>AR Objects</a>: shows how you can add real AR objects with a given latitude and longitude and properties. Also shows how you can detect clicks on objects. Uses a hard-coded "fake" location and hard-coded objects, and you can rotate the three.js camera using the mouse, so will work on a desktop or laptop.</li>
+<li><a href='03-ar-objects/index.html'>AR Objects</a>: shows how you can add real AR objects with a given latitude and longitude and properties. Also shows how you can detect clicks on objects: when an object is clicked a popup displaying the object name appears. Uses a hard-coded "fake" location and hard-coded objects, and you can rotate the three.js camera using the mouse, so will work on a desktop or laptop.</li>
+<li><a href='04-api-communication/index.html'>API Communication</a>: shows how you can communicate with a live GeoJSON API and create AR objects from the GeoJSON returned. Objects are clickable, as in example 3. Requires a real mobile device as it uses the sensors to detect device orientation.</li>
 </ol>
 </body>
 </html>