Docs: deprecates articles index (!4093) · Merge requests · GitLab.org / GitLab · GitLab

See the general Documentation guidelines http://docs.gitlab.com/ce/development/doc_styleguide.html

What does this MR do?

Last MR for https://gitlab.com/gitlab-org/gitlab-ce/issues/41138
Ports https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/16469 to EE
Adds EE-only articles from the list