Add subcategories

[aradomski]

I would be nice if you add subcategories feature. Example:

1. Image Processing:
   • lib
   • another lib
   • Image blur
     • Image blur lib 1
     • Image blur lib 2
2. Other Category

[vbauer]

Hi @aradomski, I was thinking about it, but we have not got too much projects now, so we can just split category on few. Maybe it will be implemented in future.