flatten :: Collection -> Collection
import { flatten } from 'conductor'
const array = [1, [2, [3]]]
flatten(array) // [1, 2, 3]
import { flatten } from 'conductor'
const object = { a: { b: { c: 3 } } }
flatten(array) // { 'a.b.c': 3 }
import { flatten } from 'conductor'
const set = new Set([1, [2, [3]]])
flatten(set) // Set{1, 2, 3}
import { flatten } from 'conductor'
const map = new Map([['a', new Map([['b', new Map(['c', 3])])])
flatten(array) // Map{ 'a.b.c' => 3 }