Update to CircuitPython 6 - i2c_device breaking changes

fix LSB constants + add is_ready property

Merge pull request barbudor#1 from mcauser/patch-1

Fix expired Discord link

fixes for sphinx

fixed wrong register access for channels 2 and 3

tested with CircuitPython 4.0.0-rc1

adding files to comply with Adafruit Community Library Bundle

this one should be ok now

Initial commit.

On-going tests on CPX/CPy4.0.0beta5.