Add link to tutorial

Author: keerlu

firebase/notifications-example/README.md

@@ -1,6 +1,6 @@
 ## How to send web push notifications to a browser with Firebase
 
-This example project shows you how to send TalkJS's web push notifications to a browser with Firebase.
+This example project accompanies our [Set up web push notifications with Firebase Cloud Messaging](https://talkjs.com/resources/set-up-web-push-notifications-with-firebase-cloud-messaging/) tutorial.
 
 > [!TIP] > [Download this example project as a zip file](https://github.com/talkjs/talkjs-examples/releases/latest/download/firebase.notifications-example.zip)