Rpi.gpio2

Fixed some small things:

f339a1b Bump lxml from 4.7.1 to 4.9.1 (59)
c92a545 small tweaks (58)
894b503 fix: matching shebangs for all files (54)
2707c71 rpi4 support tested, update tests (51)
127a49d change in-repo project name to RPi.GPIO2 (50)
f8caa5f Makefile: fix typo (48)
0e761de Add CNAME for custom docs domain; gitignore latex byproducts (46)
47d6ae5 Add HTML rendering of spec (45)
7af7bc0 Documentation edits - Section 4.1 (44)
3f47744 Persistent GPIO permissions (43)

This time the PyPi links will work ;)

Identical to the previous release but with all constants needed by gpiozero now properly exposed.

Exposes some previously unexposed constants.

This library should now be ready for use.