* Especially for splits, we need the ability to
unpair all paired devices as sledgehammer
if we need to "reset things", and doing so via
keymaps isn't suitable.
* Allows shields to define a collection of key
positions that if all held 2 seconds after
startup, will unpair all existing pairs for the
device.
* Service for split peripheral to report
position state to split central.
* Updated advertising info.
* Behavior for split BT until we have a proper
event system.
* Add initial event manager implementation,
roughly mimicking Nordic's API.
* Add `position_state_changed` and
`keycode_state_changed` events.
* Hook up HID and keymap to new events
instead of using behaviour global event
crazy.
* Use extra comptible = "zmk,behavior-global" to add
behaviors to global bindings for event notification.
* Implement mod-tap, as a keymap binding and global one
to skip tap if other keycode pressed while held.
* Start of work of focusing on out-of-tree user keymaps.
Add ZMK_CONFIG support.
* General external configuration supported via ZMK_CONFIG,
which should point to a configuration directory.
* Priority order of overlay files to select.
* ${SHIELD}_${BOARD}.overlay
* ${SHIELD}.overlay
* ${BOARD}.overlay
* default.overlay
* Equivalent search order for .conf files for initial Kconfig
values.
