Simplify playground URL, fix tutorial omission

index.html

@@ -32,7 +32,7 @@
 <ul>
   <li style="font-weight: bold;">Read <a href="overview">the overview</a></li>
   <li style="font-weight: bold;">Read <a href="tutorial">the tutorial</a></li>
-  <li style="font-weight: bold;">Try out <a href="https://playground.cosmopolite.org/cosmopolite/static/debug.html">the playground</a></li>
+  <li style="font-weight: bold;">Try out <a href="https://playground.cosmopolite.org/">the playground</a></li>
 </ul>
 
 <h3>Components</h3>

tutorial.html

@@ -39,7 +39,10 @@
   <li>Create an <a href="https://developers.google.com/appengine/docs/python/config/appconfig">app.yaml</a> file for your application.</li>
   <li>Add a cosmopolite include to your app.yaml file:
 <pre>includes:
-- cosmopolite</pre></li>
+- cosmopolite
+
+inbound_services:
+- channel_presence</pre></li>
   <li>Start the application in your SDK client</li>
 </ol>