Improve Kubernetes installation docs

Closes #37056

See merge request !13836

Merge branch '37266-nomethoderror-undefined-method-current_application_settings-build-failed-30837482' into 'master'

`current_application_settings` belongs on `Gitlab::CurrentSettings`

Closes #37266

See merge request !13955

Only update the sidebar count caches when needed

See merge request !13878

Don't show references to Pages when not available

Closes #34864

See merge request !13888

Changes the password change workflow for admins.

Closes #28938

See merge request !13901

The initializers including this were doing so at the top level, so every object
loaded after them had a `current_application_settings` method. However, if
someone had rack-attack enabled (which was loaded before these initializers), it
would try to load the API, and fail, because `Gitlab::CurrentSettings` didn't
have that method.

To fix this:

1. Don't include `Gitlab::CurrentSettings` at the top level. We do not need
   `Object.new.current_application_settings` to work.
2. Make `Gitlab::CurrentSettings` explicitly `extend self`, as we already use it
   like that in several places.
3. Change the initializers to use that new form.

Optimize system note service specs

See merge request !13958

Fix the /projects/:id/repository/files/:file_path/raw endpoint to handle dots in the file_path…

Closes #31470

See merge request !13512

Migrate Repository.FetchRemote to Gitaly

See merge request !13625

Decrease ABC threshold to 55.25

See merge request !13904

Removes disabled state from projects dropdown in dashboard page

Closes #37179

See merge request !13933

Adds a tooltip to the branch name

Closes #36917

See merge request !13925

Decrease Metrics/PerceivedComplexity threshold to 17

See merge request !13947

Resolve "Predefined Variable GITLAB_USER_NAME"

Closes #26692

See merge request !13824

Use google-protobuf 3.4.0.2

See merge request !13796

* master: (65 commits)
  Upgrade mail and nokogiri gems due to security issues
  Link out to stackoverflow answer on setting swappiness
  Document swappiness recomendations in the requirements doc
  Fix invalid attribute used for time-ago-tooltip component
  Update latest artifacts doc
  Add changelog entry for flipping verify_certificates
  Default LDAP config verify_certificates to true
  Update share project with groups docs
  remove accidental console.log from karma tests
  update specs to match reorganized monitoring components
  Remove tooltips from new sidebar
  Use `git update-ref --stdin -z` to delete refs
  Don't use public_send in destroy_conditionally! helper
  Remove unused expressions policy from ci/cd config
  Simplify code for appending strategies in CI/CD config
  Raise exception when simplifiable ci entry incomplete
  Add changelog entry
  Fix MySQL failure for emoji autocomplete
  max-width for lazy-loaded images (this was removed in the original MR through merge resolution most probably)
  Make namespace dropdown on new project page consistent
  ...

Make merge request version dropdowns consistent

See merge request !13590

Make namespace select dropdowns consistent

See merge request !13626

Remove accidental console.log from karma tests

See merge request !13936

Default LDAP config verify_certificates to true

Closes #33662

See merge request !13915

In this instance its subgroups, and given we can't deploy it, we
shouldn't allow it to be shown.

Fixes gitlab-org/gitlab-ce#34864

New syntax for CI/CD job triggering policy that supports variables expressions

See merge request !13769

Fixed fly-out nav jumping

Closes #36699

See merge request !13690

Upgrade mail and nokogiri gems due to security issues

See merge request !13662

Document swappiness recomendations in the requirements doc

See merge request !13943

Rename prometheus Vue components

See merge request !13938

Make namespace dropdown on new project page consistent

See merge request !13628

- `Gitlab::Shell.fetch_remote` now takes a `Gitlab::Git::Repository` instead

Increase z-index of dropdowns

Closes #36766 and #36866

See merge request !13889

Fix invalid attribute used for time-ago-tooltip component

Closes #37163

See merge request !13899