Enable tree shaking for date-fns

• Introduce modules index file and add it to package.json as main
• Add docs

See http://www.2ality.com/2015/12/webpack-tree-shaking.html

[existentialism]

Somewhat relevant… but I created a babel plugin that saves some keystrokes. It translates:

import { distanceInWordsToNow, differenceInYears, format } from 'date-fns';

to

import distanceInWordsToNow from 'date-fns/distanceInWordsToNow';
import differenceInYears from 'date-fns/differenceInYears';
import format from 'date-fns/format';

https://github.com/existentialism/babel-plugin-date-fns

Usual caveat of it working fine for our internal projects, but it could definitely use more feedback/usage.

(Also happy to transfer over to the date-fns org if interested!)

[avocadowastaken]

@kossnocorp 👍 it would be great to use like import {parse, format, max, min} from 'date-fns' in future without worrying about bundle size