Merge branch...

Merge branch 'eread/split-user-email-address_related-api-topics-off-from-main-user-api-docs' into 'master' 

Split user email address-related API topics off from main user API docs

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/167111



Merged-by: Marcel Amirault <mamirault@gitlab.com>
Approved-by: Marcel Amirault <mamirault@gitlab.com>
Co-authored-by: Evan Read <eread@gitlab.com>