TODO:
• add preferences to config.h
• complete the README
* edit commented keymap diagrams for clarity in dual function keys
* define initial config.h and add rules.mk for mouse key support
* fix redundant line after implementation of tap_code()
* fixed key_timer declaration, added README and rules
* formatting of keymap
* add CTPC to config
* cycle thumb keys to favor center position
* modify config.h for temporary Pro Micro compatibility
* remove superfluous call to use serial; homebrewed mod tap keys are still broken with OSL
* merge _SYS and _MEDIA on new Z_SYS key
* ALT_OP example of new MT macro complete
* initial narze-inspired MT fixes in PRU
* add (currently superfluous) custom keycode for the _SYS layer
* rudimentary `OSL` symbol macros that immediately register the mod and fail to reset the oneshot layer, but do output the proper keys—fix both of these things
* remove permissive hold to improve tapping performance
* remove calls to `clear_oneshot_layer_state()`, as they have no effect inside `process_record_user()`. Tapdance appears to be the way forward.
* final commit before tapdance code; correct layout in comments
* initial tapdance code for shifted mod taps
* add numeric and ergo NUM layers and pinky shifts for keycuts
* add TD() wrappers to tapdance codes and clean up commented layout guides
* add faux return to cur_dance to allow compilation - TODO: research what the default clause should be in cur_dance
* update commented schematics for better readability
* add backspace and delete to lockable layers, Z_SYS -> SYS_Z for consistency, fix schematic errors
* add `DOUBLE_SINGLE_TAP` to tapdance cases to allow doubling of the single tap character without waiting tapping term