* Add bindings to allow creating multiple physical layouts that specify
their key's physical attributes, and the matching matrix transform
and dependant kscan to use.
* Synthesize a basic physical layout if none specified, for backwards
compatibility.
* Update matrix transform API to explicitly pass in the selected transform
to the API instead of using a fixed chosen transform.
* Move kscan subscription and handling into the physical layout code, so
that selecting a different physical layout at runtime can also use the
correct kscan instance.
* Add `physical_layouts.dtsi` file to include so you can use the
pre-configured `&key_physical_attrs` for adding you layout keys.
* Refactor Kyria into separate left/right "revisions"
of the Kyria shield, and include central
kyria.dtsi file with common definition.
* Fixes for keymaps to work fully with matrix
transforms that override effective rows/columns.
* Add ability for matrix transform to do row/col
offsets, which is needed for split keyboards.
* Basic Clueboard Californai Macropad shield definition.
* New "direct" KSCAN driver that supports non-matrix direct
wiring for switches, needed for macropad that doesn't have
a matrix at all.
* Some renames for existing KSCAN GPIO driver to make the implied
"matrix" part explicit.
* 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.
Peter Johanson