Update the "Why choose" list

This is a start. 

Need more things. I would like to see a list for the vast API included in the last bullet point. I don't know the complete list. Maybe: sprite (atlas, sheet), actions, animations (including skeletal), particles, transitions, timers, events (touch, keyboard, accelerometer, mouse), sound, file IO, persistence
Added a list of examples for the vast API available

This list needs to be updated.
Merge pull request #17 from kidproquo/master

Make the why choose list more comprehensive