Add documentation for setting default compliance framework for a group

What does this MR do and why?

• This MR adds the documentation for the feature that was released via MR !101502 (merged)

Screenshots or screen recordings

Screenshots are required for UI changes, and strongly recommended for all other merge requests.

How to set up and validate locally

Visit the docs locally http://gdk.test:3005/ee/user/group/manage.html#set-a-default-compliance-framework and verify the changes.

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.

Related to #375036 (closed)