ESM fix

[tpluscode]

Fixes #9

In addition to type: module, the modules must all be referenced with .js extension. As a side note, I can highly recommend using eslint-plugin-require-extensions which ensures the extensions are used

The second commit is a little unrelated but it's the minimum I had to do to have the compilation work. Since you do not lock on a specific version of dependencies, I got type errors from @types/babel__traverse. Most likely caused by an old version of typescript, hence I added v5 to the dev dependencies. Let me know if you'd like this handled differently

[TomasCarlson]

@andreasbm would appreciate this merge :)