@ecto It's a neat idea, but I'm not sure that really works for me. I really want to be able to hand the completed Retropie over as a stand alone solution.
@everyone else...
I've been doing some searching and reading. It appears that this has been suggested several times before. But from what I gather, EmulationStation lacks a window manager that any existing pdf manager will be expecting.
So, if a pdf reader is too difficult, how about a full screen picture viewer?
Sure, storing text instructions & images as an image is going to take up more space than a pdf. But mostly these are going to be scanned images of the instructions that shipped with the game in the first place.