Merge branch 'docs-indexes-ci-1' into 'master'

Rename CI YAML index file

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/180508



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