Features:
- 6 output channels
- Master BPM
- Separate divider or multiplier per chennel (from /32 to x24)
- Random (currently only for on beat pulses)
- 1 input for external modulation (currently hardcoded to channel 6)

TODO:
- random for any division (long press encoder)
- External clock
- Switch to U8G2 for screen
- Save state to EEPROM when stopped
- swing
- settings (input mode, pulse length, modulation targets)
- Design PCB

Timer library available here
https://github.com/PaulStoffregen/FlexiTimer2

KiCad SSD1306 display component
https://github.com/pforrmi/KiCad-SSD1306-128x64