Update/fix/reorganize the documentation files for the databalanceanalysis package

[mrfmendonca]

I noted the following problems:

• some of the classes don't have a documentation for the constructor class
• some bullet points aren't formatted properly
• the entire documentation of this package is contained in a single page. Maybe it would make sense to spread it out into multiple pages and create some sort of hierarchy among them

I believe it would be a good idea to just go over the docs for this package and make sure that everything is in order.