Add PCB dimensions

[mintydev789]

When I tried ordering the PCBs, I was asked for the dimensions and the thickness, which are not specified here. Please specify them. According to PCBway the dimensions of the USB type A version are 43.8x16mm.

[mintydev789]

It would also be nice to have the other required specs, like the number of layers (I assume it's 2), minimum track/spacing, surface finish, etc.