feat: lint and pre-commit hook with Husky and eslint

[Sembauke]

Checklist:

• I have read freeCodeCamp's contribution guidelines.
• My pull request has a descriptive title (not a vague title like Update index.md)

Closes #XXXXX

[socket-security]

New and removed dependencies detected. Learn more about Socket for GitHub ↗︎

Package	New capabilities	Transitives	Size	Publisher
npm/@typescript-eslint/[email protected]	Transitive: environment, filesystem	+34	7.13 MB	jameshenry
npm/@typescript-eslint/[email protected]	Transitive: environment, filesystem	+26	2.35 MB	jameshenry
npm/[email protected]	Transitive: environment, eval	+47	4.85 MB	benmonro
npm/[email protected]	Transitive: eval	+65	9.19 MB	ljharb
npm/[email protected]	environment	0	118 kB	gnoff
npm/[email protected]	filesystem Transitive: eval	+62	4.98 MB	ljharb
npm/[email protected]	filesystem Transitive: environment	+31	3.27 MB	testing-library-bot
npm/[email protected]	environment, filesystem Transitive: eval, shell, unsafe	+59	9.72 MB	eslintbot
npm/[email protected]	environment, filesystem, shell	0	3.61 kB	typicode
npm/[email protected]	Transitive: environment, filesystem, shell	+22	1.1 MB	okonet

🚮 Removed packages: npm/[email protected], npm/[email protected]

View full report↗︎

[huyenltnguyen]

I haven't tested the changes yet. Will pull down and test the PR a little later today 🙂

[ojeytonwilliams]

@huyenltnguyen I had to fix a few errors, but nothing that required me to change the functionality, just types. I hope that's okay!

If I messed anything up, please let me know/push a commit.

[ojeytonwilliams]

Thanks for putting this together, @Sembauke.

I made a few tweaks, so I'll explain the justification:

• Similarly to the main repo, treat eslint warnings as errors (otherwise they're likely to be ignored)
• Use recommended rules for all plugins. They're generally good defaults, so we should use them until we have a reason not to
• Add eslint . to lint script. Otherwise CI will not run it.