I'm working up a wiki description of the project, with images and some simple instructions and... wow! GitHub is *really* easy to use!
I'm very impressed with the easy interface and simple actions to edit the wiki.
I can download the wiki to my local system, make edits locally, then upload to GitHub with ease. There's no waiting 45 seconds for each individual image, there's no file->select process for each individual image or file, and I can get a local preview live (without having to save/reload).
Once the GitHub wiki is in good shape, I'll copy/paste some of the text and images back into the Hackaday.io project. The Hackaday.io site has limited space for presentation, so it'll be in abbreviated form. The GitHub site allows multiple pages in wiki format.
As part of the documentation blitz, I've been going through the project as a newbie, cutting and assembling the holders, trying to find problems with the directions and clarirfying ambiguous steps.
I've figured out a good GitHub format that melds images and text in separate columns, a'la Tufte. I think it looks pretty good, and now that I know the arcane steps to make this happen on the Hackaday site I'll probably port that over.