added fan control and button handling (hard-/soft-shutdown) to the firmware

firmware: initial firmware commit, includes uart receive protocol handling (tx not tested yet!), pwm on rgb leds, fan pwm still missing, first shutdown functionality

electrical: pcb redesign for better fit of components, transistor level shifter moved away from dc/dc, smd rectifier instead of tht one, cancelled out snubber, isp moved away from edge so the attiny can be programmed with the board installed on the raspberry pi

mechanical: added first housing design - now fits into printing space

Merge branch 'master' of https://github.com/stonetronics/stoneAssistant

updated frontplate design -> too big for 3d printer

Update readme.md

Added PCB for power management and pwm

Refactoring

lower profile design