[Feature Request]: Consider bringing back the CEM lookup

[Matsuuu]

As @open-wc/create is now updated, and they're adding the analyzer to the starter, it might be worth considering to add the CEM lookup to the analyzer. This could be done in the same bunch in which we go through node_modules.

It could look up paths from the root till the current page url.

e.g.

http:localhost:8080/custom-elements.json
http:localhost:8080/foo/custom-elements.json
http:localhost:8080/foo/bar/custom-elements.json

[Matsuuu]

Implemented the lookup like described. Leaving open in case I come up with other ways that would be useful