message: Update alerts_reports.mdx
  Slack requires `chat:write` as part of "OAuth & Permissions" for the slack integration to be able to post messages.
diff: @@ -38,6 +38,7 @@ To send alerts and reports to Slack channels, you need to create a new Slack App
  3. Go to "OAuth & Permissions" section, and give the following scopes to your app:
  - `incoming-webhook`
  - `files:write`
  + - `chat:write`
  4. At the top of the "OAuth and Permissions" section, click "install to workspace".
  5. Select a default channel for your app and continue.
  (You can post to any channel by inviting your Superset app into that channel).
  