[Suggestion] Digirig Mobile PiZero HAT

Hi,

I am delighted with the DigiRig project, thanks for the effort and time to make it work!

I often use Digirig Mobile to control radio stations via Raspberry, so I realized that version B of this board could be a Raspberry Pi (Zero) HAT. It would simplify things a bit and enable us to store the whole Raspberry Pi setup in a much smaller package.

Thanks!