* For now, to be used for FrankenKyria, where both
matrix halves will be attached to the same MCU, but
should be a stepping stone to proper split support
once we have a kscan driver over a split transport.
* Implement multiple instances for mock kscan driver.
* Properly allow includes for keymaps to allow defining
custom keycodes, and then adding them to the
keymap.overlay file.
* Fix keymap.c loading after build refactor.
* Fix for deactivating a layer working properly.
* Fix default keymap to put transparent in proper spots to
make raise/lower keycodes work as expected.
* Add custom raise/lower keycode handling to default
keymap.
* Move all headers to `include/zmk` directory.
* Update includes to reference them properly.
* Add `keymap.c` file from keymap, if found.
* Toplevel CONFIG_ZMK_BLE aggregate config setting.
Pete Johanson