RRT Documentation + Doc Generation

[jgkamat]

Right now the RRT has much less documentation than I'd like (the RRT is one of the most useful parts of our codebase, since it's modularized). We need to try to make thorough docs for the rrt.

Once we have most of the way done to this, I'll add documentation generation so we can have a RRT docs site we can link to on our README, just like robocup-software and robocup-firmware.

This is a good beginner issue, especially for new members interested in path planning, if you were ok with just reading some code.

See #55 and #48.

• Document why we use Dequeue instead of a vector.
• Document hotkeys, e.x., those listed in Added new hotkeys for the RRT Interface #58

#36 is a subissue of this issue.

[kevinatorchen]

Feel free to unassign me to this issue if someone else wants to work on this. I am not sure if/when I would be able to work on this.