Update messaging.md

Author: jamesdaniels

docs/messaging.md

@@ -1,7 +1,7 @@
 <img align="right" width="30%" src="images/cloud-messaging-illo_1x.png">
 
 <small>
-<a href="https://github.com/angular/angularfire">AngularFire</a> &#10097; <a href="../README.md#developer-guide">Developer Guide</a> &#10097; Realtime Cloud Messaging
+<a href="https://github.com/angular/angularfire">AngularFire</a> &#10097; <a href="../README.md#developer-guide">Developer Guide</a> &#10097; Cloud Messaging
 </small>
 
 # Cloud Messaging