Merge branch 'nagyv-rss-release-feed' into 'master'

Add "Track releases with an RSS feed" section to docs

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/153249



Merged-by: Amy Qualls <aqualls@gitlab.com>
Approved-by: Amy Qualls <aqualls@gitlab.com>
Co-authored-by: Viktor Nagy (GitLab) <vnagy@gitlab.com>