Commit 1cc0d4638e

0.21.0

Four built-in site themes — `plain`, `blog`, `wiki`, `docs` — compiled into the
binary and selected with `site.theme`, which writes the chosen one to the output
root as `theme.css`. A minor release because it adds a config key and a `theme`
template variable; nothing already written stops working.

Opt-in: the default is empty, and a site that names no theme builds exactly what
0.20.2 built. The v0.20.2 documentation tree renders byte-identical output under
both versions, which is the check that matters for a release whose whole content
is a new way to produce different output.

The documentation site is the first user, and switching it over is also the
worked example the guide points at: the `docs` theme plus three `--orgo-code-*`
overrides, which is all `docs/style.css` now contains.

Layout: unified · split