Make the library tree-shakeable

[YuukanOO]

By using a bundler to provide 2 entrypoints, one exporting module as esnext and the other as commonjs should make the library tree-shakeable and lighter in certain cases.

[Vinnl]

Small tip: just exporting ES modules is not enough to make it tree-shakeable. Bundlers will also need to know for sure that importing such a module does not cause side effects. See here for some docs on how to tell them that: https://webpack.js.org/guides/tree-shaking/#mark-the-file-as-side-effect-free

(A good way to check whether it works is to view your package at https://bundlephobia.com/ and see if it could detect the separate modules.)

[YuukanOO]

Thanks @Vinnl ! I've already add the sideEffects: false in the package.json. I'm also using bundlephobia a lot :)

[YuukanOO]

Hmmm I guess I should distribute this lib as an ES module after all to keep things easier.