Ahodges/doc/doc1119

@shnayder @WatsonEmily @dsjen @srpearce @stroilova here's the initial draft for the gender demographic data. I don't have access to real data yet, so can't quite finish up the screen-shot-and-its-interpretation piece. (Suggestions on a good illustration welcome)
I feel like the phrase "have the option to" is kind of clunky. I understand that it's there to indicate that a set of options exists and that students don't have to select an option, but I wonder if we could say "Students can optionally provide demographic data" (with similar text elsewhere). I'll just mark it here but the comment applies to each "have the option to" in these files.