instant kkrma

... opl3 eurorack thingie / things i don't need.

• "core" pcb tested and working

• "control" pcb tested and working

• TD: ymf262, yac512 footprints might be a bit wider. firmware etc.

• teensy 3.x isn't all that suitable ... (= stm32f4 / something with more pins would have made things easier; and why use a yahama chip ... ?)