Document the codebase

[ihsan314]

Right now, most of the code present in the codebase has not been updated for more than two years. In those two years, many of the maintainers have moved on from the team and have probably forgot details regarding their implementation. Much of it might be easily adaptable to the 2021 CIRC, so we should make an effort to understand it, maintain it, and become the experts for future years. Also moving on, we should leave behind good documentation to maintain the success of UBC Snowbots.