Where to put ACL permission for addons?

How to use the ACL permission for the moderation addon (or maybe any addon for the matter), I want to allow a group to unpublish entries. Where should I put this:

groups:
  MYGROUP:
    moderation:
      publish: true
      unpublish: true

I would like to be a global permission for all Collections.

Bummer. Is there documentation for this?

It goes in your config file. Your posted code is for /config/config.yaml. If you use a /config/config.php, you have to modify it to match that format.