Add support for scoped packages

[micahjon]

First of all, thanks for this super nifty extension.

I noticed it wasn't working well for scoped packages: @orgname/packagename
https://www.npmjs.com/package/@babel/core
https://www.npmjs.com/package/@webcomponents/template

So I forked it and tweaked getPackageName() to handle this case. If you'd like me to submit a PR, I'd be happy to. micahjon@eb4066b

[cristianbote]

Hey @pranksinatra thanks for submitting this really appreciate it! 😄
It looks awesome! Feel free to open a PR when you're ready. Looking forward!

[micahjon]

Sweet, just submitted PR #6