Merge branch 'docs-lyspin-code-cov-doc-improvements' into 'master'

Restructures code coverage docs

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/179914



Merged-by: Marcel Amirault <mamirault@gitlab.com>
Approved-by: Marcel Amirault <mamirault@gitlab.com>
Approved-by: Hordur Freyr Yngvason <hfyngvason@gitlab.com>
Approved-by: Thomas Randolph <trandolph@gitlab.com>
Reviewed-by: Hordur Freyr Yngvason <hfyngvason@gitlab.com>
Reviewed-by: Marcel Amirault <mamirault@gitlab.com>
Co-authored-by: Lysanne Pinto <lpinto@gitlab.com>