Started oop terminology.
Wrote first exercise, added classes to all_exercises_challenges.
Started closer_look. Links to other relevant sections.
Rethinking overall approach.
Rewrote entire 'What are classes?' section.
Revised terminology section, added general_terminology subsection.
A simple method, exercise.
Finished 'A closer look at the Rocket class.'
Merge pull request #54 from ehmatthes/starting_classes

Starting classes