Refactor according to 61B style guidlines and add javadoc

[jason-lin]

So this is called a pull request. The idea is that any new features or new code you add is developed on separate branches (in my case, "doggie-penguin-refactor"), and then merged to the branch "master." However, it's always a good idea to have someone review your code before you do that, and this process is called a pull request.

So you can look through my code and comment on anything you want (click on a particular line of code to leave a comment). Anything in green is stuff I added and anything is red is stuff I deleted. If it's all to your liking, you approve it by leaving a comment and I'll merge it into master. If it's not, tell me what to change and I'll make the change(s) and have you re-review it. :)

[jason-lin]

Took a break from studying and added some dancing 🐧 and some jumping 🐶. Check out the branch locally to see what happens!

git checkout master
git pull origin
git checkout doggie-penguin-refactor