Initial exploration of split BLE service.

* 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.

app/boards/shields/kyria/kyria.dtsi

@@ -4,6 +4,7 @@
  * SPDX-License-Identifier: MIT
  */
 
+#include <behaviors/split_bt.dtsi>
 #include <dt-bindings/zmk/matrix-transform.h>
 
 / {