TODO

Set #main-content > main min-height so the footer never appears in the middle of the page (e.g., 404 page: https://djvill.github.io/APLS/files/blah%20blah)
- Something to do with finding height of
  + and maybe also .main-header and doing some math
404 issue link: Prefill some values (isaacs/github#99 (comment))
Add glossary
- Mark words as <span class="glossary">, have them link to anchors on a glossary page

Fun but not necessary

Switch from light mode to dark mode
- https://just-the-docs.github.io/just-the-docs/docs/customization/#switchable-custom-scheme
- https://dev.to/whitep4nth3r/the-best-lightdark-mode-theme-toggle-in-javascript-368f
Callouts: Add icon to ::before based on (e.g.) site.note.icon
- This is tricky because it's an SVG and it's hard to target ::before w/ JS.
- Prob easier in CSS/Sass if Liquid variables allowed there