Gracefully handle Javascript

This is a different issue because mdpress already ships with a js folder when you compile whereas it doesn't have an image folder.

We can:
- Symlink all the files from the js directory directly into js folder. I don't like because you could have collisions. Could be done via Yeoman (wait for new version for spawnCommand) or Grunt (wasteful to do it everytime server is ran.)
- Create a (user-)scripts folder and symlink it into the project. This works better for me because you avoid the collisions issue. It's weird to have both a scripts and a js folder, but ideally the user doesn't need to access the project folder as it will all be hidden behind Grunt.