Add wind forecast to the weather widget.

[DaveDixon]

Is there an existing feature request for this?

• [X] I have searched the existing issues

Your feature request

Here in New Mexico, the wind forecast is often as important, and sometimes more important, than the temperature forecast. The baseweather widget can be easily modified to expose the forecasts for wind speed and wind bearing for inclusion in the forecast section of the weather widget. The baseweather default for these two entities can be blank (rather than defaulting to the dark sky sensors), making the behavior consistent with previous versions.

[DaveDixon]

I have code and documentation changes ready for a pull request. The documentation change includes documentation for forecast entities not previously documented explicitly.