Merge branch 'brytannia-main-patch-69c8' into 'main'

Add notes on setting up AI Gateway url

See merge request gitlab-org/gitlab-development-kit!5344



Merged-by: Jon Glassman <jglassman@gitlab.com>
Approved-by: Nathan Weinshenker <nweinshenker@gitlab.com>
Approved-by: Jon Glassman <jglassman@gitlab.com>
Reviewed-by: GitLab Duo <gitlab-duo@gitlab.com>
Co-authored-by: Tetiana Chupryna <tchupryna@gitlab.com>