README.md in web-push-3.0.0 vs README.md in web-push-3.0.1

- old
+ new

@@ -3,10 +3,12 @@
 [![Gem Version](https://badge.fury.io/rb/web-push.svg)](https://badge.fury.io/rb/web-push)
 ![Build Status](https://github.com/pushpad/web-push/workflows/CI/badge.svg)
 
 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)).
+
 ## Installation
 
 Add this line to the Gemfile:
 
 ```ruby
@@ -176,10 +178,10 @@
   endpoint: "https://fcm.googleapis.com/gcm/send/eah7hak....",
   message: "A message",
   p256dh: "BO/aG9nYXNkZmFkc2ZmZHNmYWRzZmFl...",
   auth: "aW1hcmthcmFpa3V6ZQ==",
   vapid: {
-    subject: "mailto:sender@example.com"
+    subject: "mailto:sender@example.com",
     pem: ENV['VAPID_KEYS']
   }
 )
 ```
 