* Created an itsy bitsy rp2040 board support package adapted from the bsp of the qt py rp2040. Special thanks to ithinuel for help in matrix
* Changed the board description so it doesn't match the qt py rp2040
* Changed blinky.rs to itsy_bitsy_blinky.rs and ran changes through cargo fmt
Bring in line with atsamd-hal GPIO v2
Copied as much as possible. Docs lifted mostly as-is.
Also add sample BSP for the Feather RP2040 in boards/feather_rp2040
May include a few random fixes from currently futile attempt to get doctests working.