Remove demo files from NPM publishing on all elements and themes

[markcaron]

Remove demo files from NPM publishing on all elements and themes

[mwcz]

Going even further, we should remove tests and maybe even the src/ dir from the published artifact, leaving only the things necessary for production use.

[kylebuch8]

I'm not sure about removing the demo files. I think it makes sense to leave them so developers can refer to them if they want. I use the README files and example files in node_modules directories all the time.

[mwcz]

Closing, but can be re-opened if anyone is interested.