Merge branch 'main-patch-f006' into 'main'

Add a Runner glossary to the documentation (docs)

See merge request https://gitlab.com/gitlab-org/gitlab-runner/-/merge_requests/3996



Merged-by: Ashraf Khamis <akhamis@gitlab.com>
Approved-by: Gina Doyle <gdoyle@gitlab.com>
Approved-by: Ashraf Khamis <akhamis@gitlab.com>
Approved-by: Gabriel Engel <gengel@gitlab.com>
Co-authored-by: fneill <fneill@gitlab.com>
Co-authored-by: Darren Eastman <deastman@gitlab.com>