* master: (67 commits)
  Documentation: Frontend Building Checklist
  Fix a documentation typo for GitLab pages
  Refactored activity calendar
  Respect visibility options and description when importing project from template
  Resolve "Improve tooltips of collapsed sidebars"
  Update Container Scanning documentation
  Fix typo in vue.md
  Fix specifying a non-default ref when requesting an archive using the legacy URL
  Fix direct_upload when records with null file_store are used
  Upgrading gitlab-gollum-lib and rouge
  Check Gitaly when running `rake dev:setup`
  Update ProjectStatistics#build_artifacts_size synchronously without summing (#41059)
  Fix label links update on project transfer
  Resolve "Get rid of branch element all in bottom bar in WEB IDE"
  Rename #qa slack channel to #quality in docs
  Resolve "Show `failure_reason` in jobs view content section"
  Fix N+1 queries when loading participants for a commit note
  [Rails5] Fix `User#manageable_groups`
  [Rails5] Avoid type casting in uniqueness validator
  Add index to file_store on ci_job_artifacts
  ...