Update to latest jade/deps

The purpose of this is to make it super easy to contribute to the docs, which will only promote express all the more.

I've moved over from `make` to `gulp`, which will work on any os. I've also update to the latest jade, to be current to the docs. Also updated the `readme`, which includes one less for building. 

Note: In the future I'll probably setup a watch/reload on template change.