Support imports into frontend projects

[tiagosiebler]

This is something to modernise, supporting seamless imports to frontend projects without needing to build a js bundle with the webpack config in the repo.

Right now the only semi-documented method for using this module in the browser is to generate a js bundle using webpack, and then including that with a script tag (#144). It should be as simple as npm install then import from 'binance'. The same way backend projects use this module.

If anyone wants to look into what needs to happen to support this, please do! PRs welcome.