Instead of requiring one separate document for every version (which is
created by release managers), we now use a single document for both
Community Edition and Enterprise Edition. This allows developers to add
guidelines right away, instead of release managers having to determine
what to add.

Version specific upgrading instructions are placed in a separate
section. This prevents instructions from lingering around for many
versions should a developer forget to remove them. This also ensures
that all instructions are kept in a single place, instead of being
spread across different documents.

A minor downside is that CE and EE guidelines now live in the same
document, which could cause merge conflicts. Since we are working
towards a single codebase, this should only be an issue until we merge
the codebases together; something we expect to do in the coming months.

This commit also removes all old upgrading instructions, but these can
still be accessed using Git branch specific URLs (included in the
updating README).

Move permission check of manual actions of deployments

Closes #52412

See merge request gitlab-org/gitlab-ce!24660

Move manual actions permission check to BE

See merge request gitlab-org/gitlab-ee!9422

Add Javascript analyzer

See merge request gitlab-org/gitlab-ee!9498

Fix spelling and other minor improvements

See merge request gitlab-org/gitlab-ce!24813

Update index.md

See merge request gitlab-org/gitlab-ce!24698

Port of CE community contribution

See merge request gitlab-org/gitlab-ee!9383

Anchor link was incorrect

See merge request gitlab-org/gitlab-ce!24922

docs: capitalization fixes in Gitaly docs

See merge request gitlab-org/gitlab-ce!24994

Update dotNet test task to upload test results on failure

See merge request gitlab-org/gitlab-ce!24591

Update comment about legacy pipeline triggers

See merge request gitlab-org/gitlab-ce!24998

Fixes technical debt issues for cluster domain

Closes #57397

See merge request gitlab-org/gitlab-ce!25010

Fix visible backticks on code block /geo/disaster_recovery/index.md

See merge request gitlab-org/gitlab-ee!9467

docs: improve per-repository deploy keys

See merge request gitlab-org/gitlab-ce!24207

Documentation for Multi-Env feature flags

Closes #8621

See merge request gitlab-org/gitlab-ee!9385

Merge branch 'docs-multiple-environment-feature-flags' of gitlab.com:gitlab-org/gitlab-ee into docs-multiple-environment-feature-flags

Regenerate gitlab.pot

See merge request gitlab-org/gitlab-ee!9496

Improve NFS benchmarking doc to include read performance test

See merge request gitlab-org/gitlab-ce!24874