Add Cheat Sheet PT

PDF completed following @fadamiao's [contributions](https://github.com/github/training-kit/pull/87).

![pt-01](https://cloud.githubusercontent.com/assets/352082/3222564/d32eef26-f017-11e3-9bc1-b258d2d3f512.png)
![pt02](https://cloud.githubusercontent.com/assets/352082/3222563/d32b097e-f017-11e3-98e5-297992de75ad.png)