Fix doc (section was included in the middle of another section)
Fix https://docs.gitlab.com/ce/user/search/#search-history => "Search history" should come after "Shortcut" - the shortcut is an h4 for the h3 "Issues and merge requests per project"
Also, link to milestones filtering: https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/10812#note_27827765