Add prettier?

[pdehaan]

Not sure if we care about auto-formatting code. It feels a bit excessive in places, and we have some places which may need tweakin'.

"format": "prettier '**/*.{css,js,json}' --trailing-comma=all --ignore-path=.eslintignore --write",

Since we'd be using a nearly identical list of ignores for .prettierignore and .eslintignore, I just stuck with one, but not sure we want to auto-format the package.json file.

[motin]

+1

[motin]

@pdehaan I played around with this a bit, but it seems that prettier is so opinionated that it results in eslint errors. If you find a working combination of prettier and eslint rules, I'm all for using prettier (or some other formatter)

[motin]

Actually, https://github.com/prettier/prettier-eslint is based on running prettier + eslint --fix and that fixes the eslint issues, so here is a commit that adds npm run format using both prettier and eslint --fix

[motin]

This has been addressed in #73