Adds the Onionprobe Role into Ansible Galaxy

Tasks

• Create the GitHub mirror, as currently seems to be the only supported repository hosting service.
• Redirect pull requests and issues from GitHub to GitLab (similar to tpo/onion-services/onionbalance#34 (closed)).
• Do an initial push in the GitHub mirror.
• Setup project description in the GitHub mirror as "Onionprobe Ansible Role -- mirror of https://gitlab.torproject.org/tpo/onion-services/ansible/onionprobe-role/ -- please create issues and pull requests there".
• Setup an automatic mirror to https://github.com/torproject/onionprobe-role (similar to tpo/tpa/team#41356 (closed)).
• Setup Ansible Galaxy Namespace including admins from TPA (tpo/tpa/team#41897 (closed)).
• Include the Onionprobe role at the Ansible Galaxy, by importing it here.
• Update the documentation.
• Cleanup test role import (with the wrong role name).
• Ensure the GitHub mirror automatically receives tags. Status: could not reproduce the issue in other repository/project; maybe an echo from this issue.