redrew the diagram from scratch.

I noticed the previous image I'd been using, taken from Wikipedia user
nojhan, was dual-licensed under GNU FDL and CC-BY-SA -- yet the
Wikipedia article about the FDL says it's incompatible with Creative
Commons licenses... I wasn't sure what that would mean for my intended
use of the graphic, if I was allowed to use it or if I'd need to apply
the FDL to all of Roshambo5 or what, so I decided to play it safe and
just make my own diagram.
corrected coordinates for image <map>.

I needed to switch "rock" and "scissors" to their proper places for the
updated roshambo diagram.