* Add blackbill interconnect metadata.
* Add config/overlay for upstream blackpill boards to work with ZMK.
* Add pillbug board.
* Updated new shield docs.
Co-authored-by: Cem Aksoylar <caksoylar@users.noreply.github.com>
* Document the Seeed(uino) XIAO interconnect
* Add metadata files for two upstream boards, XIAO and XIAO BLE.
* Add conf and overlay files to properly configure the boards
for ZMK use.