* restructure converters
each converter is its own keyboard and different hardware variants are different subprojects.
remove (seemingly) old method of loading layouts from main Makefile
* call led_set_kb() from overridden led_set()
* put converter back into one folder
* revert some structure changes to bring in line with #1784.
Also attempt to get the BLE thing more properly integrated.
Also also fix led_set() to call led_set_kb().
