Add missing link to firewalled-clients FAQ in behind-nat question
in https://support.torproject.org/operators/behind-nat/ we suggest to read the 'firewalled-clients FAQ' but we don't provide any way to find that FAQ.
We should find out where it is, and link it on the text:
If your relay is running on a internal net you need to setup port forwarding. Forwarding TCP connections is system dependent but the firewalled-clients FAQ entry offers some examples on how to do this.