(non-enforced) section on prerelease versions?

Since PVP doesn't have explicit support for prereleases, there are a few techniques that have been practiced in the community, e.g. GHC:

* https://downloads.haskell.org/~ghc/9.4.1-alpha1/ is in fact `9.4.0.20220501`

This allows PVP compliant update once the real `9.4.1` is released.

I don't think the spec should enforce any of that, but what if we provide this as a non-enforced practice recommendation.

VSCode has something similar, where `major.EVEN_NUMBER.patch` marks a release and `major.ODD_NUMBER.patch` marks a pre-release: https://code.visualstudio.com/api/working-with-extensions/publishing-extension#prerelease-extensions

So in our terms, `X.Y.EVEN_NUMBER.` is the pre-release for `X.Y.ODD_NUMBER` or somesuch?