fix: module bundling (#1081)

[javiertury]

Here is a way to bundle the project with bili, which is a tool based on rollup aimed to simplify the bundle process. As you can see in bili.config.js the configuration is minimal. It also needs the plugin rollup-plugin-typescript2 and generates definitions automatically at dist/index.d.ts.

The bundles are:

• A CommonJS bundle dist/index.js for package.json#main
• An ES Module bundle dist/index.esm.js for package.json#module
• An AMD bundle dist/index.amd.js. Bundles meant for CDNs should be put in package.json#browser, however I'm not familiar with the AMD format and I think it requires special tools to work with, so I will leave package.json#browser blank for now.

[TheJoeSchr]

I forked and yarn pack this branch and tested it locally as tarball and can confirm it works and fixes #1081

Would it be possible to merge this so the package works again?

[javiertury]

In my opinion this issue is important. It makes the library no longer compatible with bundlers like webpack and rollup.

@Akryum, I don't know if this PR has been assigned to anyone for review.

I am open to hear some feedback. If you prefer rollup to bili, I can modify this PR to use rollup instead.

[Akryum]

Thanks for the PR! I'm using esbuild on the branch to build.