Add Probability of precipitation

[jwsp1]

According to openweathermap, Probability of precipitation is distributed by one-call-api. It is available hourly (hourly.pop) and daily (daily.pop). Not 100% sure though if it's available in the free version?

(sorry, this is meant to be labeled as "enhancement", not "bug")

[woheller69]

Probability of rain is a parameter which will probably not be understood by most users. I therefore have no plans to add this parameter to keep things simple.

https://www.weather.gov/media/pah/WeatherEducation/pop.pdf

[kojid0]

I understand that you are afraid that it will be too complicated for some. Simplicity is important, but I personally also find the rain probability a useful piece of information to see if the rain icon really brings rain, or just clouds with a higher probability.

Anyway, if you want to implement it (as an option), here's an upstream PR to fix this issue if you want: https://github.com/SecUSo/privacy-friendly-weather/commit/b2e13041b4beda20eed78309a33f43726e404826