do I make an image span the entire page?

How do I make an image span the entire page of, say, an 8.5 x 11 PDF?

Note: My margins are set to 1" x 1" x 1" x 1." Yet, I need the image to span the entire page as seen below in Scrivener’s own User Manual for macOS: How did they do this using Scrivener only?

Well to be clear about one thing, I don’t use Scrivener only to create final quality PDFs; I don’t myself feel that is the role of a writing tool; I use LaTeX to typeset the user manual. For the cover page I generate a full-size PDF file in Photoshop which is inserted as part of the boilerplate. The chapter and part breaks are done by modifying the background colour of the page, and by laying out the text using floating boxes, not by using images.

There is no way to actually do that with Scrivener all by itself. The document has one global margin setting and all content must fit within that area.