add code bundlers, like webpack

[anna1go]

• It would be cool if we added support for the latest and greatest to this, like support for es6 and webpack, babel and all the new hot JavaScript libs. Def just a nice to have and play around with, but worth doing if we have time.

[anna1go]

Relaying on in browser support for JavaScript modules as described here for now....

https://jakearchibald.com/2017/es-modules-in-browsers/