Create R.html


![the-r-series](https://cloud.githubusercontent.com/assets/538575/3709300/e03ee842-1452-11e4-9158-986d64589b4e.png)
R Introductory motivational slides prepared with @danlwarren.
Need to include attached image for reference book's cover page as stated in slides.
Why the span6? That makes it use only half the available screen width.