[Tor-BSD] updates to obsd-relay manual

[Tim Kuijsten]

I've done some updates to the openbsd-relay manual[0]. Only after I had 
opened up a pull request I saw that others have done the same[1] and 
only yesterday I found out there are some instructions on the official 
Tor wiki as well[2]. I'm not sure who to contact about my proposed 
changes but at least the GitHub repo seems a bit inactive.

-Tim

[0] https://github.com/torbsd/torbsd.github.io/pull/19
[1] https://github.com/torbsd/torbsd.github.io/pulls
[2] https://trac.torproject.org/projects/tor/wiki/TorRelayGuide/OpenBSD