Merge branch 'docs-clean-tables' into 'main'

Clean up tables in runner docs

See merge request https://gitlab.com/gitlab-org/gitlab-runner/-/merge_requests/5548

Merged-by: Roshni Sarangadharan <[email protected]>
Approved-by: Roshni Sarangadharan <[email protected]>
Co-authored-by: Marcel Amirault <[email protected]>

Author: Roshni Sarangadharan