[Suggestion] only show categories which are not empty

The categories like Emulators, Tools when selected, at least for me show games, it is because they are empty. It would be better if they were not even selectable if there is no corresponding pkgi_x.txt file, or if the default file had nothing for that category.

In addition to this, the All category could possibly have an indicator as to what type each item is, reason being, say I wanted to display a game and all its DLCs in one place, I would see them under all but not know which is the game and which is the theme and which is the DLC.