[Feature Request] Padding variable for whole date-picker element

[krechtern]

Hey, currently we have the option so set the --adp-padding variable to define a padding. But this variable is used for the padding of the the nav and content element. So currently it is only possible to set a padding for the whole air-datepicker element with overriding the style. Would be nice to have a variables for this too!

I really love all the variables and customization options! Keep it up!