Add eslint w/ airbnb styleguide and pre-commit

[GroverW]

I thought this was super helpful and maybe worth scoping out. Since you're using React I think there's a bunch of plugins you might need.

Info on possible plugins: https://github.com/react-boilerplate/react-boilerplate/blob/master/package.json

But basically

1. npm install --save-dev eslint@6.8.0 eslint-config-airbnb [ADD OTHER PLUGINS] I had issues with the latest version (hence @6.8.0), but you may not
2. npm install --save-dev pre-commit
3. in package.json - well, you can follow basically what they did in react-boilerplate, but an example:

   "scripts": {
   < ... other scripts >
   "eslint": "eslint --ignore-path .gitignore",
   "eslint:fix": "eslint --ignore-path .gitignore --fix",
   "lint": "npm run eslint -- . ",
   "lint:fix": "npm run eslint:fix -- . "
   },
   "pre-commit": [
   "lint:fix"
   ],

4. create .eslintrc.json next to package.json. And the most basic config would be (but probably gotta follow react boilerplate):

   {
   "extends": [
       "airbnb"
   ]
   }

[GroverW]

Forgot to add - once you have the scripts setup you can do "npm run eslint -- . " to test. As far as I can tell you can't run eslint directly unless you have it installed globally, so you gotta setup a script.