Add docs for linking to external dashboard

Closes #57171

See merge request gitlab-org/gitlab-ce!27950

- To user/project/operations
- And cross-link in ci/environments

Fix border radius of collapse discussion btn

See merge request gitlab-org/gitlab-ce!29217

Video links for SSoT audit

See merge request gitlab-org/gitlab-ce!29400

Turn avatar-counter into a mixin with optional border-radius

Adding labels to note event payload.

Closes #33064

See merge request gitlab-org/gitlab-ce!29384

Make margin between buttons consistent

Closes #62974

See merge request gitlab-org/gitlab-ce!29378

[ci skip]

List ssh-ed25519 example

See merge request gitlab-org/gitlab-ce!28090

Fix Fogbugz Importer not working

Closes #33530

See merge request gitlab-org/gitlab-ce!29383

Clarify that performance bar is not always on

See merge request gitlab-org/gitlab-ce!28287

Externalize strings of email page in user profile

See merge request gitlab-org/gitlab-ce!28587

Add backtraces to Peek performance bar for SQL calls

See merge request gitlab-org/gitlab-ce!29394

Make option dropdown button to match adjacent button

Closes #62144

See merge request gitlab-org/gitlab-ce!29096

[CE for Part 3] Update IDE file mirror service (ce utils)

See merge request gitlab-org/gitlab-ce!29360

This stopped working in GitLab 11.11 when we upgraded to Rails 5.1.
Rails 5 changed ActionController::Parameters to return an Object instead
of a Hash. The old behavior was deprecated in Rails 5 but finally
removed in Rails 5.1

Since the controller wasn't updated properly, the callback endpoint
quietly failed with the message, "Could not connect to FogBugz, check
your url".

To fix this, we need to call `to_h` on the `import_params` to access the
Hash. We also need to do this for the user map and permit specific keys.

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/33530

Add project Dependency List sidebar entry

See merge request gitlab-org/gitlab-ce!29189

Add more info to deleted user documentation

Closes #62674

See merge request gitlab-org/gitlab-ce!29321

SSOT - Added link to video to enhance docs

See merge request gitlab-org/gitlab-ce!29398

Clarify that GitLab CI token does not have write permissions

See merge request gitlab-org/gitlab-ce!28089

Just as we have backtraces for Gitaly, we should also have backtraces
for SQL calls. This makes it much easier to find the source of the SQL
call and optimize N+1 queries and other performance issues with an
endpoint.

Add OpenID Connect troubleshooting docs

See merge request gitlab-org/gitlab-ce!29379

Edit Admin Area's index for SSOT

See merge request gitlab-org/gitlab-ce!29327

Edit "Visibility and access controls" to meet SSOT guidelines

See merge request gitlab-org/gitlab-ce!29171

Edit "Subgroups" for SSOT

See merge request gitlab-org/gitlab-ce!29318

Single source of truth for merge requests docs

Closes #61516

See merge request gitlab-org/gitlab-ce!29269

- Edit pages under user/project/merge_requests and
  add the relevant types in the frontmatter.
- Clean up descriptions.

Based on https://gitlab.com/groups/gitlab-org/-/epics/1280