- Now putting chapters inside "<article>".
- Doing rendering of context.md + chapter markdown, instead of rendering
  the whole book at once.
- messed about with CSS rendering of headings

This marks the start of the workings: technical notebook project.

a) it's hard
b) people are scared of it
c) fuck it

Who doesn't love hovery stuff and blinding white backgrounds?

...this was actually blowing up on more than one result from find(1).

Also adds a few dependencies to Makefile, comments out some formatting
in render.pl, sets up a demonstration of converting a program from
specific -> general, perhaps lays groundwork for a discussion of the
utility of diff(1) in software terms, which seems like a good transition
back to extant literary tooling.