What metrics to collect for tor?

[stp-ip]

Is this a BUG REPORT or FEATURE REQUEST?:
feature

What happened:
Currently we don't collect anything specific for tor.

What you expected to happen:
Not sure yet. Ideas?

Partially copied from: txtdirect/txtdirect#246

[stp-ip]

Finish discussion within this milestone and then use next milestone to implement metrics using the caddy metrics aka not our own prometheus instance.