tor: add option for contact info

The Tor Project would like relay operators to be transparent. Giving contact information helps them distinguish potential bad actors from actual volunteers. It also makes it easy for the Tor Project to reach out to operators if some error occurs. We should add a textbox so that FreedomBox users can submit their email addresses if they run a relay.

torrc:

## Administrative contact information for this relay or bridge. This line

## can be used to contact you if your relay or bridge is misconfigured or

## something else goes wrong. Note that we archive and publish all

## descriptors containing these lines and that Google indexes them, so

## spammers might also collect them. You may want to obscure the fact that

## it's an email address and/or generate a new address for this purpose.

#ContactInfo Random Person <nobody AT example dot com>

## You might also include your PGP or GPG fingerprint if you have one:

#ContactInfo 0xFFFFFFFF Random Person <nobody AT example dot com> `

https://gitlab.torproject.org/tpo/community/relays/-/issues/18