Add a help page of common non-puzzles with explinations

It may be nice to have a page for common "not a puzzles". A short write-up with pictures and examples and explanations of why certain things are not puzzles, but may sometimes be confused with one. For example many lotto pickers, marble machines, and do-nothings are misidentified as some kind of puzzle. Have a small paragraph identifying each type of non-puzzle, with a small list of photo examples (possibly sourced from the community).