doc: rename file to advocacy-ambassador-program.md

PR-URL: #56046
Reviewed-By: Rafael Gonzaga <rafael.nunu@hotmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Marco Ippolito <marcoippolito54@gmail.com>
Reviewed-By: Richard Lau <rlau@redhat.com>

Author: tniessen