Be ready to run a C compiler.
Running ./update.sh up writes an up-to-date list of the site's files to “files.json”.
Running ./update.sh tube generates “files.html” from “files.json”, if “files.json” exists.
Running ./update.sh tube up does both of the above in the order they're written above, then uploads “files.html” to https://publictransit.neocities.org/kaa/files.
Hand-tested on amd64 OpenBSD 7.2, amd64 Devuan Linux 4, amd64 Windows 10 19042, and armv7l Alpine Linux 3.16.
Specifics are included in the file “readme”.