Write the example config, including every current config option for every module

We will need to keep this file up to date every time we add a config option or change a default.

I wrote this specifically because Ashton wanted to play around with the server but there was no docs on the config options.
I had a talk with @ElementalAlchemist about this a little while back and we agreed it would be a good idea to advertise setting +x on connect here, and then add a note that HostCloaking has to be loaded for that to work.