Standardize file headers and provide example of "perfect source code file"

[krisnova]

Right now all of our code is very disparate, some files have apache 2 headers, some do not, some have large amounts of comments, some are empty, etc, etc

This issue has 2 parts

1. Document and provide an example of a "picture perfect" Aurae .rs file
2. Begin working backwards from the example, and implement the required changes for each of our source files

Do we need to have clippy tags? If so, which ones are the "correct" ones to use?
Do we need to include an apache 2 header with the ascii art? if so can we please automate/add the headers globally.
Do we need documentation as in #211 everywhere? is there an example we should be using?

[krisnova]

See also: https://github.com/rust-lang/rustfmt