Add Makefile with build (default), clean, and force

The `force` target will ensure that latex re-runs, since you gotta do
that with latex all the damn time before it gets things right.
ignore latex build crumbs
Replace template with sections, add language ref.
Add section on the canvas.
tighter title spacing
Revise canvas section to be more approachable.

Apparently it's quite easy for me to write very dry, mathy, academic
prose. Shocking, I know.