New Site Generator

After a month of testing, I’ve cut over the site engine to my new Go-based generator, which lives almost entirely inside GitHub Actions and uses a rather convoluted process to minimize the number of moving parts and dependencies. I still expect some minor breakages and regressions, but the new engine is much faster and a bit more flexible than the old one, plus it does away with the need to have a separate build server and the associated maintenance overhead. Let’s see how it goes, shall we?