Additional API for weewx weather station.
This is a follow up from #70 of adding weewx support to this plugin.  I'm not really sure where to go but need some help finishing this up.  I forked this repo edited one of the apis (weather underground) to read the json that weewx is capable to produce.  The edited api is [here](https://github.com/CHAMLEX/homebridge-weather-plus/blob/master/apis/weewx.js), the changes I made are that the apikey is utilized for the sitename/path and location for the file name so if your website is called weewx the would be the apikey and the location would be the file name (without extension) so for example this should call http://weewx/homebridge.json and scan the json file.  I also included a sample of the json file that i formatted that matches homebridge and included a few more fields that weewx can use that match up to the plugin.  The JSON sample response is [here](https://raw.githubusercontent.com/CHAMLEX/homebridge-weather-plus/master/sample_response.json).  If I need to reformat the response that's not difficult just not sure how to get/test the edited api and ideally get it added.  Thanks!