support for Double

[AKiniyalocts]

It would be great to have support for Double values instead of just Integer values as the backing type for the number picker.

Thanks for your work, very nicely done and useful library. The platform pickers are very behind, this is a breath of fresh air. 👍

[Hesamedin]

Ya, I need to have step size 0.5 and I cannot use this lib I guess :(