zmk.scm (make-zmk):Update to ZMK 0.2.1.
(special-bindings): Add more bindings.
(mouse-bindings): New.
(zmk-name->string): Fix for more complex definitions in special-bindings
and mouse-bindings.
(zmk-keymap) [input-processors]: New argument.
(/input_processors/temporary-layer): New.
(/behaviors/modifier-mousebutton): Rename to …
(/behaviors/modifier-mb): … this.
(/behaviors/scroll-tap, /behaviors/toggle-layer,
/behaviors/toggle-layer-on, /behaviors/toggle-layer-off,
/behaviors/toggle-layer-flip, /behaviors/mb-hold-click,
/behaviors/layer-hold-switch): New behaviors.
(/macros/zoom, /macros/hold-mb-activate-layer,
/macros/release-mb-deactivate-layer, /macros/4-layer-switch): New macros.
(/behaviors/4-layer-tap-dance): Use /behaviors/layer-hold-switch instead
of /behaviors/layer-hold-tap.
(redox-neo-keymap): Add mouse emulation layers und use new bindings,
macros, input-processors. Change vertical-combos.