Implement Prettier

[JasonEtco]

Hey folks, I heard about this on your amazing podcast spot and thought about it a little. Have y'all seen Prettier? I think we could make use of that here. If you're not interested, I'd love to build it out as a separate app thats entirely prettier-based but I think it could just be used here.

[tunnckoCore]

Yup. I recently suggested creating prettier-bot prettier/prettier#3262, but the response was quite good - StyleJS. It seems good too, but i feel it does too much and also don't works well with eslint, probably because is not using prettier-eslint, but it is must have.

I am interested in starting work here too. Few things:

• respect all eslint's config files *
• respect all prettier config files *
• use prettier-eslint by default, or some sort of auto-detection - to use it only if eslint config is found in repo, otherwise use only prettier

* - resolver similar to cosmiconfig should be implemented that works with github api. It's not so hard btw, following the code of pretty-config which is a lot smaller and better. I even sit for 2 minutes with cup of coffee and visualized all the things in my head. ProTip: use safe-eval.

I believe the resolver should be implemented in the core.