* master: (33 commits)
  Changing the smallest of typos
  Remove `<script>` and `<template>` from CHANGELOG.md
  Fix icon color and btn-group alignment of discussion buttons
  Simple docs fixes
  Fix button type
  Changes after review
  fixed karma tests
  Removes group_avatar & group_label_subscription from global namespace
  Fix CSS in load more participants
  Fix the description of the new branch created by an issue's new branch button
  Fix a small typo in the delete merged branches documentation
  spec fixes
  Remove Sherlock usage from the performance bar
  moved to eventHub to manage creating new files removed an ID from the CSS
  Use the new buttons for creating groups and projects in QA tests
  fixed eslint 🙈
  added feature spec
  fixed failing title test
  fixed bug with tabs not switching correctly
  failing spec fixes
  ...

Add note about coming group milestone support

See merge request gitlab-org/gitlab-ee!3195

(EE-Port) Circuitbreaker backoff and retries

See merge request gitlab-org/gitlab-ee!3191

Remove problematic H1 from alpha_database.md

See merge request gitlab-org/gitlab-ee!3201

Simplify Geo installation docs: tracking DB is enabled by default now

Closes #3827

See merge request gitlab-org/gitlab-ee!3200

EE- remove new sidebar stuff

See merge request gitlab-org/gitlab-ee!3197

Port of "Remove Autosave class from global namespace" to EE

See merge request gitlab-org/gitlab-ee!3198

Closes #3827

[ci skip]

Rename the Alpha PG HA documentation to just the PG HA documentation

See merge request gitlab-org/gitlab-ee!3151

Refactor `have_http_status` into `have_gitlab_http_status` in the specs

See merge request gitlab-org/gitlab-ee!3183

Update using_docker_images and merge_requests docs

See merge request gitlab-org/gitlab-ee!3188

That way we can enable the circuitbreaker for just one host at a time.

Instead of only checking once within a timeout, check multiple times
within a timeout.

That means with a timeout of 30 seconds and 3 retries. Each try would
be allowed 20 seconds.

The circuitbreaker now has 2 failure modes:

- Backing off: This will raise the `Gitlab::Git::Storage::Failing`
  exception. Access to the shard is blocked temporarily.
- Circuit broken: This will raise the
  `Gitlab::Git::Storage::CircuitBroken` exception. Access to the shard
  will be blocked until the failures are reset.

Add loading button -- EE merge edition

See merge request gitlab-org/gitlab-ee!3165

Geo: Don't retry repositories or files until everything has been backfilled

Closes #3810

See merge request gitlab-org/gitlab-ee!3182

Reduce the quiet times between scheduler runs on Geo secondaries

Closes #3813

See merge request gitlab-org/gitlab-ee!3185

Encompasses designs from
 - https://gitlab.com/gitlab-org/gitlab-ce/issues/23206#note_43355199
 - https://gitlab.com/gitlab-org/gitlab-ce/issues/29985#note_30417407

[ci skip]

[ci skip]

CE upstream - Wednesday

See merge request gitlab-org/gitlab-ee!3167

Fix setting Geo sync capacity in the admin panel

See merge request gitlab-org/gitlab-ee!3184

Update Prometheus gem to fix problems with other Processes overwriting current metrics file

Closes #36714

See merge request gitlab-org/gitlab-ce!14827