Add ESLint, improve code, and fix scripts

[SpreeHertz]

Made all files cleaner and fixed package.json scripts.

Also added nodemon as test.

[SpreeHertz]

 "scripts": {
        "start": "node .",
        "test": "node index.js"
    },

test and start are pretty much the same, so replaced them with nodemon and ESLint.

I can also clean up README.md if you want.