chore: Linting

[maxwellmattryan]

Description of change

• Adds ESLint and Prettier as root-level dependencies (use yarn lint and yarn format[-check])
• Adds rustfmt for linting *.rs files
  • Currently only in the CI workflow
• Adds GitHub Action for running a linting job on any PR and pushes to develop
• Adds pre-commit Git hook via Husky that checks format and then lints
• Changes .github/CONTRIBUTING.md with new linting step and updating CI link
• Re-formats code with yarn format in root dir (NOTE: linting errors are everywhere so they will be in a separate PR)

NOTE: .svelte files do not mix well with Prettier for some reason, so they are omitted. It is mainly just .ts files that have the formatting.

Links to any relevant issues

None

Type of change

• Chore (refactoring, build scripts or anything else that isn't user-facing)

How the change has been tested

Tested on:

• Ubuntu (20.04)
• Windows 10 (19042.1110)

Change checklist

• I have followed the contribution guidelines for this project
• I have performed a self-review of my own code
• I have made corresponding changes to the documentation
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes

[rajivshah3]

Nice!

[rajivshah3]

Thanks for adding rustfmt! Just a few suggestions

[rajivshah3]

Great work!