I think this should be part of the docs. I just read it and it's clear.

Do you know it’s better described than in the glossary, or the typeclass/intro page of the docs?

The typeclass/intro as it gives a good background before heading to the practical.

Just left some notes with some minor style adjustments. The link to the other typeclass doc is fine, but the example link in that document gives a 404 😕

I fixed the 404!