Plugin / accessory logging

[cbrunnkvist]

The readme says:

You can now start Homebridge, use the -D flag, so you can see debug log messages in your plugin

which is nice and all, but I can't see any clear way of how to see only the related messages in the log - does logging use the debug module under the cover, so that it is possible to use the variable DEBUG= e.g. DEBUG=my-plugin:* to filter, or something like that? Either way I think it would be helpful during troubleshooting for both users and devs if the best practice logging was described a just a wee bit more in this template.