Merge branch 'master' into 39957-redirect-to-gpc-page-if-users-try-to-create-a-cluster-but-the-account-is-not-enabled

Execute quick actions when creating MR from issue

Closes gitlab-ee#4277

See merge request gitlab-org/gitlab-ce!15810

Add new “Troubleshooting Git” page to General documentation

See merge request gitlab-org/gitlab-ce!15903

Document how to remove assignees, labels, and milestones form the issue and MRs API

See merge request gitlab-org/gitlab-ce!15664

Make usage of SSH keys in CI/CD more clear

Closes #25716

See merge request gitlab-org/gitlab-ce!15790

Updates dependencies license list

See merge request gitlab-org/gitlab-ce!15905

10.3 gitignore and license templates

Closes #10

See merge request gitlab-org/gitlab-ce!15901

10.3 update guide

Closes #10

See merge request gitlab-org/gitlab-ce!15900

10.3 "Installation from Source"

Closes #10

See merge request gitlab-org/gitlab-ce!15899

In CE, this does nothing - the `MergeRequests::BuildService` will, at the time
of writing, never return a description for this case.

In EE, a project can have a default MR template, which will be returned by the
service. Previously we were only using the description passed in the params,
ignoring any already set on the object. Now we fall back to the one set on the
object if there was none in the params, allowing quick actions to be executed
from default MR templates when creating an MR from an issue.

Remove page-with-new-nav class

See merge request gitlab-org/gitlab-ce!15819

Export old code into es6 modules

See merge request gitlab-org/gitlab-ce!15787

Use relative URL for projects to avoid storing domains

Closes #40895

See merge request gitlab-org/gitlab-ce!15876

Resolve "Update styling of empty states"

Closes #40468

See merge request gitlab-org/gitlab-ce!15791

Resolve "Prometheus loading screen no longer seems to appear"

Closes #40285

See merge request gitlab-org/gitlab-ce!15889