Article organization

Adds show action/view for Articles and pagination. Since I couldn't find anything about pagination without using gems online (which seemed to contradict the nature of this project), I took inspiration from how @pk-nb pulled it off. Resolves #9 
My personal preference is to always choose `if` over `unless` if I can since it makes things easier and quicker to understand. Avoiding negatives in general is a rule I try to stick to actually.