Remove "create a Supademo" banner

This “Create a supademo in minutes” banner shows up in any folder or sub-folder that doesn’t have a supademo directly in it (e.g. if there’s a branching folder structure). For some folders, it means that this is taking up almost all the screen space because there’s only one or two folders in it. It ends up being very intrusive. It would be better to have it so that this doesn’t show up in sub-folders.