use correct filename in example

closes #80

README.md

@@ -175,7 +175,7 @@ This is a web notification channel that allows you to trigger client-side web no
 streams:
 
 ```ruby
-# app/channels/web_notifications.rb
+# app/channels/web_notifications_channel.rb
 class WebNotificationsChannel < ApplicationCable::Channel
    def subscribed
      stream_from "web_notifications_#{current_user.id}"