Add section describing how to connect to Tor via a bridge.

Just discovered this project, great work!

I added a small section on connecting to Tor via a bridge.  For some users, their ISP may block access to Tor and by using a bridge, they may be able to then access the network.  However, this may still not work, so users could use pluggable transports.  I can write a section on that if you guys want, but it may start to get more technical...