Add Entity Framework and Angular 2 Categories

We actually have numerous amount of EF articles already. We can't just categorize it to EF because the aforementioned category does not exist. In the case of Angular, I understand your concern, but It would be too confusing for readers to search something related to Angular 2. Remember Angular 2 is completely rewritten and the implementation is way different compared to Angular 1.x. To put it in other words, it's okay to have ASP.NET 1.x,2.x,3.x and 4.x categorized as ASP.NET. But not for the case of ASP.NET Core because it was completely rewritten and different. :)

Alright. We will create 2 new categories.

Thank you :)