npm: add package-lock.json

[eldios]

I'm trying to build a nixPkg for this repo but in order to do so, a package-lock.json file is needed.

I guess this is also a best practice in general so it's a good idea to add it anyway :)

To generate the package-lock.json file, simply run:

npm install --package-lock-only

This would be particularly important whenever there's a tag-ged release or whenever the package.json file is updated.

Thanks!

[eldios]

is there anything else you want me to do to merge the code? may I help in any other way? til I have this in the main repo (and preferably tagged as well) I can't continue the nixpkg work :)

Thanks