Convert group messages to private channel

[amy.blais]

Hi @ptyler! Thank you for reaching out.

Here is a doc with more information on this: https://docs.mattermost.com/help/getting-started/organizing-conversations.html#converting-public-channels-to-private.

Also, here is the CLI command tool that can be used: https://docs.mattermost.com/administration/command-line-tools.html#mattermost-command-move.