This is a copy of:
https://gitlab.torproject.org/tpo/onion-services/onionprobe/-/blob/1edc255d4b905264a995a503043f93b4f3238f40/configs/prometheus/prometheus-rules.yml
We'll tweak this to match our configuration
See: tpo/onion-services/onionprobe#51 team#42029 (closed)