Docs: Fix redirected link to be more direct

Closes #58620

See merge request gitlab-org/gitlab-ce!26081

Port of 51988-install-group-runner-on-group-cluster to EE

See merge request gitlab-org/gitlab-ee!10415

A runner installed on a cluster will now use the
cluster's `cluster_type` as its `runner_type`.

Support installing Group runner on group-level cluster

Closes #51988

See merge request gitlab-org/gitlab-ce!26260

A runner installed on a cluster will now use the
cluster's `cluster_type` as its `runner_type`.

Expand resolved discussion when linking to a comment in the discussion

Closes #59352

See merge request gitlab-org/gitlab-ce!26483