Add link to prebuilt images

README.md

@@ -111,6 +111,12 @@ default: "buster"
 which defines two images, *buster* and *bullseye*, and sets the
 default to *buster*.
 
+### Download pre-built images
+
+For convenience, we build Debian stable / nextstable images weekly
+with this project's CI. You can download these images from the
+project's [Package Registry](https://git.autistici.org/ai3/tools/vmine/-/packages).
+
 ### Building an image
 
 VMine can only work with QCow2 rootfs images.