Fixed a potential bug in temperature generation, not interpolating correctly...

Fixed a potential bug in temperature generation, not interpolating correctly between month transitions
Added descriptions for extreme temperatures.
Added temperature to exceptions. Can now pick specific days to be a custom temperature.
It should now always snow on christmas day. (set to -5 and heavyPrecipitation)
Added an "extreme" property for temperature range generation. It can be set per month, and currently can only happen max twice / month
Added some documentation to weather and temperature generation files
Changed name of WeatherConditions to WeatherGeneration