added DesignSpark PCB file of actor shield
added DesignSpark PCB file of actor shield

All actors are now controlled by using 3 GPIO pins only. The PCB layout
uses ULN2803A ICs for demuxing up to 24 bits. Serveral shield could be
connect to achieve more bits. The PCB could be used as an arduino
shield.

LuckyOfST/heizung,LuckyOfST/heizung