Fix #17

[59naga]

#17 (comment)
I restored the old index.js on the side of the index.mjs as the new code broke the old behavior promised by this library i.e. it is a drop-in replacement for package 'assert'. So by default it should work the same as 'assert'. Now it won't work for e.g. assert(true), but you must use assert.default(true) etc. so it's not a drop-in replacement anymore. Do you have an idea how the module exports could work in the new system as before so assert(true) could work without having to use require('assert-diff').default ?

Can delete .default using webpack's UMD (as published @59naga/assert-diff@2.0.2).

yarn add -D @59naga/assert-diff

var assert = require('@59naga/assert-diff')
assert.deepEqual({a: 1}, {a: 1}, 'this should not fail')

[pihvi]

Perfect, thanks!