Ah, you mean,
This tutorial is for how to add or remove the "*default*" "Folders" in This PC instead.

and the tutorial title should be, General Tips Add or Remove Default Folders from This PC in...

I'm confused, the first page says how to Add a folder to "This PC", but I don't see any guide on that. Is there a way to add a folder to that list that is not one of the standard ones Microsoft has...