Intl bindings

[tom-sherman]

Thought I would open this tracking issue for Intl support.

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl

[illusionalsagacity]

on the topic of rescript-js via BigInt brought up in your PR: #76 (comment)

It's worth noting that rescript-js does have some bindings to Intl and there's https://github.com/opendevtools/rescript-intl