First draft of pseudo select element

Not sure if there is anything missing in the original repo (or it's me lack of knowledge about Node.js), In the very beginning I am not be unable to  start a local development server.

So after a while, I've made a temporarily workaround, that to manually create an index.html including basic dom structures and essential scripts, then run a local python server to make it alive. That's how I get started.

As this is actually the first time I am tweaking around with a real chunk of Node.js codes, bugs, problems and something that anti-best-practices are very likely to happen here and there. Hope you could give me some suggestions after lots of facepalm, thank you very much :)

The index.html file is available here: https://gist.github.com/Vincent-Zhe-Zhang/7950287