Walk through it instead of filming it

[onatozmenn]

Closes #14, and the last box on it is answered with something other than what it asked for.

It asked for a recording that works with the sound off. A recording of this page would be a copy of what the compiler said on the day it was filmed, and this page's whole claim is that it prints what the compiler prints. The two would eventually part company, and the recording would win the argument, because it is the thing that looks authoritative.

So the walkthrough moves through the page that is already here. Five steps, a caption saying what to look at, four and a half seconds each. No sound to turn off, and nothing that only works if you can see colour: the caption carries the meaning and the section is scrolled to.

Auto-advance is off entirely under prefers-reduced-motion, and a wheel, a touch or a key ends the tour rather than fighting whoever is reading it themselves.

If a real video is still wanted later, it can be recorded of this, which is the ordering that keeps it honest.

Also fixed

The two playground links on that page still carried #0.2.1/, so the playground would have warned that the program was written against another version, for no reason: the programs did not change between tags.

tools/check.mjs now reads the version out of every share link on the site and compares it to the pin. Verified by writing 0.1.9 into one:

one-clause/index.html: links a program written against 0.1.9, and the pin is v0.2.2

_{Written with AI assistance.}