Document Review Apps

Closes #51201

See merge request gitlab-org/gitlab-ce!21574

Resolve "Link to file in Changes tab of MR no longer works for all files after incremental rendering improvement"

Closes #50347

See merge request gitlab-org/gitlab-ce!21727

Resolve "Link to file in Changes tab of MR no longer works for all files after incremental rendering improvement"

Explain the docs' CD, relating to the milestone the doc is set to vs online docs

See merge request gitlab-org/gitlab-ce!21737

Correct Gitaly config typo in update guides

See merge request gitlab-org/gitlab-ce!21821

Fix link to blog posts in docs

See merge request gitlab-org/gitlab-ce!21820

The 9.4 to 9.5 and 9.5 to 10.0 guides missed a closing backtick. This
was corrected in the 10.0 to 10.1 guide, from which subsequent guides
were written without the error.

Due to a missing `s`, a link to the blog archive
for releases was broken.

Delete container repository tags outside of transaction

Closes #51380

See merge request gitlab-org/gitlab-ce!21679

Fix rubocop Style/ZeroLengthPredicate

See merge request gitlab-org/gitlab-ce!21793

Relax the subject line requirements for commits

Closes gitlab-org/release/framework#16

See merge request gitlab-org/gitlab-ce!21811

Re-enable legacy diff notes on merge request diffs

Closes #48873

See merge request gitlab-org/gitlab-ce!21652

Remove unused constant

See merge request gitlab-org/gitlab-ce!21810

This changes the hard limit of 50 to a soft limit of 50, with the new
hard limit being 72 characters. This gives people a bit more space,
while still (hopefully) guiding them towards subject lines that are
roughly 50 characters long.

Fixes https://gitlab.com/gitlab-org/release/framework/issues/16

Fix grammar in runner-related specs, views and localisations.

See merge request gitlab-org/gitlab-ce!21691

This removes an unused constant from the
`RubyInterpolationInTranslation`. The constant was used in a first
implementation of this class.

See merge request gitlab-org/gitlab-ce!21689

Use standalone diff stats RPC on every comparison view

Closes #51477, #20282, and #49399

See merge request gitlab-org/gitlab-ce!21778

When there are many tags in a container repository, deleting them
can exceed the default 60 second idle-in-transaction timeout in
Sidekiq. We now explicitly delete them in the DestroyService
before destroying the model.

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/51380

Refactor main.js content

See merge request gitlab-org/gitlab-ce!19783

Unite green buttons under one css class

See merge request gitlab-org/gitlab-ce!21795

Re-enables merge conflicts resolution spec

See merge request gitlab-org/gitlab-ce!21654

Rename btn-new, btn-create and btn-save to btn-success
Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

Vendor Auto-DevOps.gitlab-ci from gitlab-ci-yml

See merge request gitlab-org/gitlab-ce!21775

Add wrapper rake task to migrate all uploads to OS

Closes #51571

See merge request gitlab-org/gitlab-ce!21779

Remove EE-specific lines from Plan concerns

See merge request gitlab-org/gitlab-ce!21448

Enhance some performance guideline titles

See merge request gitlab-org/gitlab-ce!21797

[QA] consolidate selector patterns (1_manage/login)

See merge request gitlab-org/gitlab-ce!21711

Improve Emoji detection in commit messages

Closes gitlab-org/release/framework#15

See merge request gitlab-org/gitlab-ce!21799

Resolve "Enable Auto DevOps by default for self managed instances of GitLab"

Closes #41729

See merge request gitlab-org/gitlab-ce!21157