Seems leaky to me… transpiling messages has nothing to do with any of the built in `Intl` APIs, its a very straight forward string parser. I'd rather that build scripts or locator stuff use the transpiler directly instead of loading up this package, setting up a global `Intl`, loading the polyfill, etc.

I think we should take @ekashida's transpiler code out of `locator-lang` and make it its own package, and write it in ES3 compatible code. From there the this package could depend on that one and built it into it's dist files.

This way we have the transpiler code in one place, it would have no dependency and can be used by our tools, and intl-messageformat can depend on it and embed it into its source.