Merge branch 'master' into bme680

Documentation/how-to-build.rst

Documentation/pycardium/os.rst

Documentation/pycardium/personal_state.rst

epicardium/ble/filetransfer.c

lib/gfx/gfx.c

preload/apps/card10_nickname/__init__.py

preload/apps/card10_nickname/metadata.json

preload/apps/lsd_nickname/__init__.py

preload/apps/lsd_nickname/metadata.json

pycardium/modules/py/ledfx.py

requirements.txt