Add ESLint

[tara-matthew]

• This PR adds ESLint
• If there are any rules you want changed let me know
• I've also added a script to run the linter
• Once you're happy I can open another PR which runs the linter

[PradyumnaKrishna]

If possible, can you please also add an option to format the files?

[tara-matthew]

Thank you for taking a look! 🥳
The --fix option in the lint script will reformat the files for you, if that's what you mean?

https://eslint.org/docs/latest/use/command-line-interface

[PradyumnaKrishna]

Lets make it two commands, one that formats the code and one that lints the code only.

[tara-matthew]

Sure thing, good idea! I'm away from my computer this evening, but will get this updated for you either later today or tomorrow 👌

[tara-matthew]

@PradyumnaKrishna Updated 👌