This uses the Feather nRF52840 tree as a base - haven't yet noticed any real issues aside from the 64Mb QSPI flash not being accessible (which makes sense given NRF port doesn't have external flash support at all yet, from what I can tell)

Documented the "weird" bits of this device at least to some level. It's definitely a unique beast - so far it looks like it's the only board in the NRF tree that flashes with pyocd (I entirely skipped flashing hex files over the DAPLink MSC, but it's allegedly supported, and it's the first piece of Micro or CircuitPython hardware to truly trip me up and teach me new electronics terms - turns out the LEDs and user button are wired "backwards" from all the other dev boards in my house :)

I expose ALL the pin names as seen in https://github.com/makerdiary/nrf52840-mdk/blob/master/docs/hardware/nrf52840-mdk-pinout-diagram-v1_0.pdf. Some of these may not entirely make sense to expose (like QSPI?) but for a first pass I decided to leave them in there, and we can trim if needed.