Revised Commit Shorthand Examples

Commit shorthand slides contained Markdown syntax errors and inconsistent content style from other slides. This addresses those problems and inconsistencies.

![screen shot 2013-09-30 at 4 46 09 pm](https://f.cloud.github.com/assets/352082/1241608/1f94ee54-2a22-11e3-8f8d-b7bbb845ddcc.png)