Document that group Owners can always create subgroups
Document that group Owners can always create subgroups

Issue: https://gitlab.com/gitlab-org/gitlab-ce/issues/30473
MR: https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/14046

axilleas/gitlabhq,iiet/iiet-git,jirutka/gitlabhq,axilleas/gitlabhq,mmkassem/gitlabhq,iiet/iiet-git,jirutka/gitlabhq,dreampet/gitlab,stoplightio/gitlabhq,stoplightio/gitlabhq,iiet/iiet-git,axilleas/gitlabhq,dreampet/gitlab,mmkassem/gitlabhq,mmkassem/gitlabhq,dreampet/gitlab,dreampet/gitlab,mmkassem/gitlabhq,stoplightio/gitlabhq,axilleas/gitlabhq,stoplightio/gitlabhq,jirutka/gitlabhq,jirutka/gitlabhq,iiet/iiet-git