Refactor of appearance/customization docs

Closes #31189

See merge request gitlab-org/gitlab!18049

Move most information regarding the appearance section
to /user/admin_area, and redirect from /customization.
Updates screenshots, information, process, etc.

Fixed cert-manager retry logic to apply correct exit code

Closes #34065

See merge request gitlab-org/gitlab!18545

Enable frozen string for spec/uploaders

See merge request gitlab-org/gitlab!18547

Partially addresses:

https://gitlab.com/gitlab-org/gitlab/issues/27703

Update Auto DevOps quickstart

Closes #33075

See merge request gitlab-org/gitlab!18356

Update guide to show new base domain loc, update images

Instructions to set your Geo Node Name

Closes #11501

See merge request gitlab-org/gitlab!18463

Use PlantUML intregration in PlantUML docs

See merge request gitlab-org/gitlab!18550

Productivity Analytics: Move daterange component to shared space

See merge request gitlab-org/gitlab!18383

- Refactor daterange component

Change Gitaly recommendations for 25k and 50k architectures in the docs

See merge request gitlab-org/gitlab!18531

EKS Cluster form static fields and security groups dropdown

See merge request gitlab-org/gitlab!17762

- Cluster name
- Environment scope
- Kubernetes version

Add end-to-end test to delete board via the graphical user interface

Closes gitlab-org/quality/testcases#226

See merge request gitlab-org/gitlab!18522

Clarify the usage of sentence case in headings

See merge request gitlab-org/gitlab!18535

License-Check approval tooltips

See merge request gitlab-org/gitlab!16371

Provide MR and Issue links through the Release API

Closes #29020

See merge request gitlab-org/gitlab!18311

Copy emojis to new destination folder

See merge request gitlab-org/gitlab!18483

Add sorting to the packages group page

Closes #13536

See merge request gitlab-org/gitlab!18062

Fix security reports test and update pipeline test

Closes #33993

See merge request gitlab-org/gitlab!18503

Fix typo in API Docs

See merge request gitlab-org/gitlab!18539

Fixes whitespace and line numbers

Closes #33911

See merge request gitlab-org/gitlab!18537

Adjust placeholder to solve misleading regex

Closes #12564

See merge request gitlab-org/gitlab!18235

Optimize SQL requests for BlameController and CommitsController

See merge request gitlab-org/gitlab!18342

Currently the full potential of lazy_author
is not used
Let's try and use lazy_author&.itself instead
of lazy_author.__sync to load authors in batches

Revert "Merge branch 'rjain-remove-old-label' into 'master'"

Closes #34042

See merge request gitlab-org/gitlab!18538

Add more Information about ModSecurity

See merge request gitlab-org/gitlab!18469

Add more context to Praefect docs

Closes #33462

See merge request gitlab-org/gitlab!18350

Remove `-o` documentation from SSH key generation

Closes #33492

See merge request gitlab-org/gitlab!18223