Microbundle Library Test

- Create a library that works in browser/node using latest technologies (esm etc)
- Hopefully work on CDN, new browsers, old browsers
- Figure out how to handle polyfills
- To fix unsupported browser stuff
- Node equilavent replacement of browser apis
- using "exports" in package.json
- and typescript equilavent

Does this bundle dependencies?
https://github.com/developit/microbundle/wiki/How-Microbundle-decides-which-dependencies-to-bundle

Things to polyfill/substitute
- fetch
- node is implementing, so may exist on newer versions
- crypto
- node vs browser?
- localStorage
- does not exit in node: see https://github.com/lmaccherone/node-localstorage

Plan

- Start with simple library, like add(a, b)
- Add more bits as I go