Add support for Graham's number

[mihaitodor]

Details here: https://en.wikipedia.org/wiki/Graham%27s_number

[Rudxain]

Easy, we just need BigInt support. According to ES, they are (theoretically) unbounded in size, so there's no need to worry about memory, as every browser must comply with the spec.

I've even wrote a function that we can use to test the code. Just call it like so:

import { Graham } from 'https://raw.githubusercontent.com/Rudxain/EsoMath.js/6ab44eae22d4b850e968a4a7a9f4c99d1a5ec9f2/src/lib/hyper.js'
const isEven = require('@samuelmarina/is-even')

isEven(Graham(64n)) //false