Add Visual Studio Code

[FranklinYu]

I would like to add the plugin for Visual Studio Code. Pull Request is the easy part; I have two questions:

1. Popularity matters? Only 15k downloads, 3 reviews.
2. Should the URL be GitHub source page or Marketplace extension page?

[jgonggrijp]

1. No problem, go ahead and submit your pull request.
2. Whichever link the authors of that plugin seem to prefer.

[FranklinYu]

@dnwhte what do you think about the second question?