Update Releases permissions docs
Update Releases permissions docs

Guest users now can read releases, except for items related to source
code.

Releated:
  https://gitlab.com/gitlab-org/gitlab-ce/issues/56838
  https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/27247

iiet/iiet-git,iiet/iiet-git,stoplightio/gitlabhq,mmkassem/gitlabhq,stoplightio/gitlabhq,mmkassem/gitlabhq,mmkassem/gitlabhq,iiet/iiet-git,stoplightio/gitlabhq,mmkassem/gitlabhq,iiet/iiet-git,stoplightio/gitlabhq