Merge branch 'docs/383178-group-protected-branches' into 'master'

Update group-level protected branches force push docs

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/167639



Merged-by: Brendan Lynch <blynch@gitlab.com>
Approved-by: Brendan Lynch <blynch@gitlab.com>
Co-authored-by: Joe Woodward <j@joewoodward.me>