Publish usable module on npm

[fregante]

I noticed that the detector has been published to npm in #98 but the file does not contain any exports and thus it cannot be imported:

typeof require('js-library-detector') === 'undefined'

It'd be great to see:

• module.exports = or export default
• some documentation (the published readme file talks about the extension instead of the library)

Here's the published content:

• lib https://www.unpkg.com/browse/js-library-detector@6.5.0/library/libraries.js
• readme https://www.unpkg.com/browse/js-library-detector@6.5.0/README.md