Usability wiki page

[richjoregonstate]

Need section on how our design does the following:

• [ ] Learnability: How easy is it for users to accomplish basic tasks the first time they encounter the design?
• [ ] Efficiency: Once users have learned the design, how quickly can they perform tasks?
• [ ] Memorability: When users return to the design after a period of not using it, how easily can they reestablish proficiency?
• [ ] Errors: How many errors do users make, how severe are these errors, and how easily can they recover from the errors?
• [ ] Satisfaction: How pleasant is it to use the design?

[jctrotter]

Done, updated the usability page.