Merge branch 'docs-add-praefect-user' into 'master'

Docs: Add user in praefect configuration

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/137964



Merged-by: Amy Qualls <aqualls@gitlab.com>
Approved-by: Amy Qualls <aqualls@gitlab.com>
Co-authored-by: David Wainaina <dwainaina@gitlab.com>