9.5.5 blogpost

Release Issue: https://gitlab.com/gitlab-org/gitlab-ce/issues/37628

These are commits from 9.5 CE that are not included in the post

https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/14083 - backport from EE
https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/14117 - update docs
https://gitlab.com/gitlab-org/gitlab-ce/commit/7733e8c3784a926e98ca54a4e29339a843af05f2 - migration to fix corrupted projecs
https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/14213
https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/13416
https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/13469
https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/13878 - this was reverted
https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/13666