Format entire project using rustfmt, update readme with how to run rustfmt and add in a job (in IDE's too)

[Proryanator]

https://github.com/Proryanator/encoder-benchmark/pull/32

rustfmt was used in the above PR, which pointed out that we don't have a way to catch/prevent mis-formatted code from getting into the code base.

This should be relatively simple to setup via adding a new github action/job.

To-Do:

• add a new job that runs rustfmt --check via docs here that will run before any other jobs for your PR. Job should block the PR and suggest running rustfmt locally to fix the formatting issues
• format the entire project using rustfmt (to establish a clean repo)
• add section to the README's Contributing section to discuss how to run rustfmt (including various ways to automatically run this in your IDE)

[Proryanator]

(how to do this in RustRover or other Jetbrains tools)

[e-dong]

This would be good to do! This will make sure the diff are cleaner in future PRs haha