This reverts commit 5e8ff010a1.
This broke all the URLs, we can't have that. (And actually, we probably don't
_want_ to make the change either. It's nicer to have all the pages in one
directory, so one doesn't have to figure out to which collection the page
belongs.)
Let's use the rough categorization of the markdown pages to add basic
sections, via Jeykll templating. Also, add in a couple of additional
links via a JSON array that lists them.
So much web development, so much wow!
