feat: analyze node modules

[thepassle]

No description provided.

[netlify]

✔️ Deploy Preview for custom-elements-manifest-analyzer ready!

🔨 Explore the source changes: fed4221

🔍 Inspect the deploy log: https://app.netlify.com/sites/custom-elements-manifest-analyzer/deploys/615c91668fc8ef0007e1c3eb

😎 Browse the preview: https://deploy-preview-129--custom-elements-manifest-analyzer.netlify.app

[thepassle]

closes #123

[thepassle]

TODO:
Some considerations as brought up in #130:
Getting the CEM from a third-party module is hard. We either have to analyze stuff in node_modules/, which may be minified code, or built code (TS) in which case we may lose type information/completeness of the CEM.

Alternatively, we could try to find the third-party's custom-elements-manifest.json file, which is also hard; if the third-party uses package exports, but doesnt list their CEM in the package exports, there's virtually no way for us to get it.

We could always try to see if the third party has a CEM (either by checking the package exports or see if they have a customElements field in the package.json), and if all else fails; analyze the package.

If a CEM does exist in the third party package, we have to merge two CEMs together:

• Change filepaths of the third party package to where we found it (e.g.: node_modules/foo)
• Apply inheritance
• Remove anything from node_modules from the 'main' projects CEM

[thepassle]

closing in favour of #142