Add Javadoc comments
WHAT
Add Javadoc comments to the whole project. All the classes and methods should have Javadoc comments.
WHY
Anyone new to the project or who wishes to understand the API should be able to see documentation of the API.
HOW
Create a new issue for the class that you choose to comment on. Then, comment the class and make a pull request.
[ ] BidService [ ] ListingService [ ] ShareUserService [ ] BookshareApiController [ ] DataWrapper [ ] FormWrapper
(More to be added ...)