UPGRADING.md in slack-ruby-bot-server-1.2.0 vs UPGRADING.md in slack-ruby-bot-server-1.2.1

- old
+ new

@@ -21,9 +21,11 @@
     add_column :teams, :oauth_version, :string, default: 'v1', null: false
   end
 end
 ```
 
+See [MIGRATING](MIGRATING.md) for help with migrating Legacy Slack Apps to Granular Scopes.
+
 ### Upgrading to >= 1.1.0
 
 #### Extracted RealTime (Legacy) Support
 
 New slack apps may no longer access RTM. Classic Slack apps can no longer be submitted to the app directory as of December 4th, 2020. In preparation for these changes slack-ruby-bot-server no longer includes RTM components by default. These have been extracted to a new gem [slack-ruby-bot-server-rtm](https://github.com/slack-ruby/slack-ruby-bot-server-rtm).