Documentation For Games #Libgdx ( if that changes anything.)

Hey Guys!
Just wondering, how you guys document your games?

I must make a “perfect” documentation of my game… Since its a college project.

Im using this GDD http://form.ironbellystudios.com/gdd-template/

Plus, i will use astah as UML Designer.Though , i will have to reverse-engineer since i coded first before Designing it ( i know its wrong but i never bealived i could make a game lol )

So what you guys think about all this?