Documentation is missing Monitor usage instructions

[djangohunt]

The docs on https://netmq.readthedocs.io/en/latest/ have no mention of the NetMQMonitor. It seems most people are just looking at the source code and unit tests to see how to use the monitor. It would be really helpful to have clear instructions on how to use the monitors. Setup and teardown would be key areas as that's where people are having the most problems.

[drewnoakes]

Would be great if you could contribute an initial doc.

I also need @somdoron or @sachabarber to give me permission on readthedocs so I can get the site updating again.