Merge branch 'tchu-create-advanced-search-migrations-styleguide' into 'master'

Create Advanced Search Migrations styleguide

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/112726



Merged-by: Kamil Trzciński <ayufan@ayufan.eu>
Approved-by: Kamil Trzciński <ayufan@ayufan.eu>
Reviewed-by: Kamil Trzciński <ayufan@ayufan.eu>
Reviewed-by: Rajendra Kadam <rkadam@gitlab.com>
Co-authored-by: Ashraf Khamis <akhamis@gitlab.com>
Co-authored-by: Terri Chu <tchu@gitlab.com>