Add CI linting

[PeterJCLaw]

This adds a large number of docstrings as well as a number of other code tidyups.

There are not intended to be any behavioural changes here, though there are a couple of places where I've changed the spelling of some logic so that it fits better.

Note: this has a small number of failures left. I'm not sure how they should be fixed, partly as they (mostly) look like they're part of code which is now dead:

• 44 odd behaviour in Robot.close meaning I'm not sure what the method is meant to do

• #42 dead Servo_get_status method which uses undefined variable

• 43 zone_script.py

[PeterJCLaw]

@Adimote and/or @RealOrangeOne what's the status of robot/zone_script.py? It doesn't really fit with this project and appears untested (at best) and possibly broken.

[RealOrangeOne]

@PeterJCLaw It's been tested locally by @Adimote, however not for a while (pre-smallpeice IIRC). I doubt it's broken, but it's highly likely in need of some improvement.

I would agree it should be in its own repo, with its own documentation, as it's never actually used in robot-api. I've extracted it out in https://github.com/sourcebots/robot-api/pull/43