Add notes about architecture to PG HA document

Closes omnibus-gitlab#2705

See merge request gitlab-org/gitlab-ee!3490

Fix in-progress repository syncs counting as failed

Closes #4053

See merge request gitlab-org/gitlab-ee!3424

Refactor cluster docs

See merge request gitlab-org/gitlab-ee!3486

Geo: Rename the old directory first when swapping out the recovered directory

Closes #4083

See merge request gitlab-org/gitlab-ee!3463

Geo: Ensure that LFS object deletions are communicated to the secondary

Closes #3962

See merge request gitlab-org/gitlab-ee!3481

Add geo hashed storage warning

See merge request gitlab-org/gitlab-ee!3480

Port of 38869-milestone to EE

See merge request gitlab-org/gitlab-ee!3484

Improve geo docs based on Sid demo

See merge request gitlab-org/gitlab-ee!3485

Disable file attachments for epics

Closes #3914

See merge request gitlab-org/gitlab-ee!3434

Remove upgraded licensed feature from list

See merge request gitlab-org/gitlab-ee!3477

Refactor  Cluster docs

Closes #39952

See merge request gitlab-org/gitlab-ce!15418

(cherry picked from commit d41e66cb)

644a2941 Add info about the installed apps in the Cluster docs
b7a01e08 Add info on creating your own k8s cluster from the cluster page
ee7ecc81 Add Ingress description from official docs
3b9773fc Change to Google Kubernetes Cluster and add internal links
bacf671a Move installation of apps higher

[EE] Update gRPC to v1.7.2

See merge request gitlab-org/gitlab-ee!3443

Geo - Move the primary node checkbox below the URL

See merge request gitlab-org/gitlab-ee!3483

EE: Fix merge_requests.source_project_id migration

See merge request gitlab-org/gitlab-ee!3476

Cap the Geo retry_at value to prevent out of range timestamps

See merge request gitlab-org/gitlab-ee!3461

Make Issue Boards sidebar subscriptions async -- EE merge edition

See merge request gitlab-org/gitlab-ee!3442

Show the current EE plan in the license details section

See merge request gitlab-org/gitlab-ee!3462

We need to make sure merge_requests.source_project_id allows NULL values
_before_ updating rows as otherwise this will lead to a NOT NULL
constraint failing.

Implement a workaround for QA mattermost failures / EE

See merge request gitlab-org/gitlab-ee!3471

Make change_access_spec.rb less likely to cause conflicts on CE to EE merges

See merge request gitlab-org/gitlab-ee!3456

Enable RequestStore in IssuesController spec to prevent N+1 warnings

See merge request gitlab-org/gitlab-ee!3356

Add Docker binaries to instance image of GitLab QA / EE

See merge request gitlab-org/gitlab-ee!3473

[ci skip]

This solves a problem where Gitaly connections through Unix sockets
would not work when a proxy was configures, even if a no_proxy setting
was specified

EE port of 38451 fe sprite icons vue component

See merge request gitlab-org/gitlab-ee!3433

Conflicts:
	app/assets/javascripts/boards/components/board_card.vue
	app/assets/javascripts/boards/models/issue.js
	app/assets/javascripts/subscription.js

Update docs to show use of high availability redis and sentinel roles

See merge request gitlab-org/gitlab-ee!3452