Slack Slash Command documentation should say it's only for self-managed

The documentation for GitLab Slack application says in a blue box at the top:

Note: The GitLab Slack application is only configurable for GitLab.com. It will not work for on-premises installations where you can configure the Slack slash commands service instead.

... but the documentation for Slack slash commands has no such block.

I believe that the "Slack slash commands" functionality is only supported on self-managed instances and is not supported on GitLab.com.

Proposal

Add a blue box to the top of the documentation for Slack slash commands saying e.g.:

Note: The Slack slash commands are only configurable on self-managed GitLab instances. They will not work on GitLab.com, where you can configure the GitLab Slack application instead.