Code: inside of the categories of case-studies

[turanlioglu]

In each category, we expect to see the case-studies in order:

Newly open, ordered with release date In-progress, ordered with due date(closer will be on top) Closed, ordered related to effort spent

And there will be simple descriptions of each case study under categories

[turanlioglu]

Category links are added, later with these links, all the related cases will be seen under the categories, the related commit: 52c9e27