https://gitlab.com/gitlab-org/gitlab/-/issues/330455

Coloring only links in the description, not titles

We might still want to highlight cross-references in
other places, but it seems that this is more scoped
to what https://gitlab.com/gitlab-org/gitlab/-/issues/330455
specifies.

Changelog: changed
MR: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/68063