Doc update for GitLab HA Geo.

Closes #4328

See merge request gitlab-org/gitlab-ee!3822

Merge branch 'ee-41291-spec-failure-on-spec-features-merge_requests-image_diff_notes_spec-rb' into 'master'

[EE] Fix a failure because we stub DiffHelper#diff_file_blob_raw_path instead of #diff_file_blob_raw_url

See merge request gitlab-org/gitlab-ee!3855

[EE] Update Ruby version to 2.3.6

See merge request gitlab-org/gitlab-ee!3848

Extend Geo Node Status with information in replication slots

See merge request gitlab-org/gitlab-ee!3621

Add detail to disaster recovery docs

See merge request gitlab-org/gitlab-ee!3845

Docs: move article Artifactory + GL to subject-related folder

See merge request gitlab-org/gitlab-ee!3862

Docs move transfer project to group ee

See merge request gitlab-org/gitlab-ee!3837

- move the section
- replace identifiers with inline links
- update settings (General settings > Advanced settings)

added link from admin Dashboard "Geo" feature/component

See merge request gitlab-org/gitlab-ee!3795

Merge branch 'ee-39246-fork-and-import-jobs-should-only-be-marked-as-failed-when-the-number-of-retries-was-exhausted' into 'master'

Fork and Import jobs only get marked as failed when the number of Sidekiq retries were exhausted

See merge request gitlab-org/gitlab-ee!3851

EE specific JS modules

See merge request gitlab-org/gitlab-ee!3828

EE Port of Basic IDE Setup

See merge request gitlab-org/gitlab-ee!3846

Signed-off-by: Rémy Coutable <remy@rymai.me>

Rename clair and sast:image references to sast:container

Closes #4359

See merge request gitlab-org/gitlab-ee!3850

Resolve "Static analysis is broken on `master`"

Closes #4406

See merge request gitlab-org/gitlab-ee!3853

Use 'preload' in export to CSV

Closes #4376

See merge request gitlab-org/gitlab-ee!3841

Add support for defining explicit dependencies to QA factories / EE

See merge request gitlab-org/gitlab-ee!3832

Update d3 to v4 to enable tree shaking (EE counterpart)

See merge request gitlab-org/gitlab-ee!3564

move groups.scss .plan-badge to ee namespace

See merge request gitlab-org/gitlab-ee!3746

Split project repository and wiki repository status in Geo node status

Closes #3735

See merge request gitlab-org/gitlab-ee!3560