Update markdown documentation for table of contents tag

Closes #202171

See merge request gitlab-org/gitlab!24535

Update links so that they  display the readme on master

See merge request gitlab-org/gitlab!24490

Fix broken link pointing to prod architecture

See merge request gitlab-org/gitlab!24544

Migrate diff_line_gutter_content_spec to jest

See merge request gitlab-org/gitlab!24545

Move 'anchor' subheadings under 'anchor'

Closes #38323

See merge request gitlab-org/gitlab!24411

The YAML page contained multiple deep sub-subheadings for YAML
anchors. A member of the technical writing team requested we
reunite these subheadings together under the 'anchor' subheading.

Geo - Spike Self-Service Framework

See merge request gitlab-org/gitlab!24498

Add unix to allowed hosts

See merge request gitlab-org/gitlab!24541

Add SAML screenshots and links

See merge request gitlab-org/gitlab!24013

Move mock data.
Consolodate mock data.

Update docs screenshots for email notifications

Closes #201926

See merge request gitlab-org/gitlab!24406

Merge branch '201554-follow-up-from-default-cycle-analytics-duration-chart-and-median-line-feature-flags-to-true' into 'master'

Resolve "Follow-up from "Default cycle analytics duration chart and median line feature flags to true""

See merge request gitlab-org/gitlab!24436

Quarantine Geo specs

See merge request gitlab-org/gitlab!24499

Issue: https://gitlab.com/gitlab-org/gitlab/issues/201948
Specs are quarantined according to time to triage

#196250 adding preload to prevent N+1

See merge request gitlab-org/gitlab!22845

Merge branch '202084-downloading-source-code-on-geo-secondary-attempts-to-write-to-the-database' into 'master'

Don't log a security event to the database on a read-only instance

Closes #202084

See merge request gitlab-org/gitlab!24537

Add debug logs to Geo E2E specs

See merge request gitlab-org/gitlab!24434

Resolve "Better documentation on import from GitHub"

Closes #18783

See merge request gitlab-org/gitlab!24507

Add https requirements to Auto DevOps docs

See merge request gitlab-org/gitlab!24482

In Rails 6, the new HostAuthorization middleware is enabled by
default (it's not enabled on other environments). It currently
allows localhost and IP addresses and we add
`Gitlab.config.gitlab.host` as additional allowed host.

When gitlab-shell makes a request via unix socket, it uses
`http://unix/<endpoint>` so the host will be `unix`. Since it's
not included in the list of allowed hosts, it gets blocked.

This adds `unix` host to the list of allowed hosts.

Standardize project fabrication on QA Plan tests

See merge request gitlab-org/gitlab!24474

Add pointer to how to contribute to managed apps docs

See merge request gitlab-org/gitlab!24484

Update to eslint 6

See merge request gitlab-org/gitlab!24413

Add project_key column

See merge request gitlab-org/gitlab!24063

Project_key will be used to identify projects when
user sends an email to service desk specific address.

Downloading the project source code on a Geo secondary
node tries to log a security event to the database
raising a  `PG::ReadOnlySqlTransaction` error.

This updates eslint and related plugins to the next major version so
that we can make use of new features.

Rough out subheading for starring projects

Closes #31142

See merge request gitlab-org/gitlab!23908

The method of starring a project has not been documented in GitLab's
documentation. This commit provides a subheading on the user/project
page explaining this feature.

Geo: Remove Sync button from Uploads UI

Closes #202032

See merge request gitlab-org/gitlab!24496

Introduce security scan model

See merge request gitlab-org/gitlab!23669

This stores scans run by Secure Products