Update README note about Pushpad gem

Author: collimarco

README.md

@@ -5,7 +5,8 @@
 
 This gem makes it possible to send push messages to web browsers from Ruby backends using the [Web Push Protocol](https://datatracker.ietf.org/doc/html/rfc8030). It supports [Message Encryption for Web Push](https://datatracker.ietf.org/doc/html/rfc8291) and [VAPID](https://datatracker.ietf.org/doc/html/rfc8292).
 
-**Note**: This is an open source gem for Web Push. If you want to send web push notifications from Ruby using Pushpad, you need to use another gem ([pushpad gem](https://github.com/pushpad/pushpad-ruby)).
+> [!NOTE]
+> This is an open source gem for Web Push maintained by Pushpad. If you want to send web push notifications from Ruby using Pushpad (the cloud service), use the [pushpad gem](https://github.com/pushpad/pushpad-ruby).
 
 ## Installation