Merge branch 'fix/cleanup'

cleanup: remove unused include, move sources to appropriate location

Merge branch 'feat/timing'

docs: rework

scripts: add bash script to build debug and release

fix: issue with systick

feat: move systick API to standalone module

docs: rework

scripts: add bash script to build debug and release

fix: issue with systick

feat: move systick API to standalone module

gpio: optimizing access by new API

Merge branch 'feature/i2c_bitbang'

feat: bring up microshell

update: microshell

docs: add heatbeat LED

feat: add LED to PA0 for heatbeat

update: microshell

docs: add heatbeat LED

feat: add LED to PA0 for heatbeat

docs

docs

wip: "view" in MVC

view: develop main screen with SOC: select fonts, x/y etc

docs: add info about using display with SPI; add thoughts about fonts

feat: hardware inversion

docs: update info about PMOLED's

tests: add scrolling line for font