I have been going through the tutorial, and found the following error. Here is the section of the tutorial in question.
So that you can see where one document ends and the next begins, there is a horizontal dividing line between sections, but if you prefer you can also display the document titles above each section by going to the View menu and selection Editor > Show Titles in Scrivenings.
I found that you actually have to go to the Format Menu > Options > Show Titles in Scrivenings to turn these on and off.