It turns out, just as I was ready to push the button on publishing this thing, that Jekyll doesn’t generate tag pages for you.
It almost does - the amount of effort to create an “other pages with this tag” page is about 20 seconds, but it doesn’t actually do it.
So, instead, I’ve had to create a
tag folder, and fill it up manually with a series of short
<tag-name>.md files. Like some sort of Neanderthal.
Ah well, the whole point of documenting more stuff is to learn.