V1alpha2 crd only docs

[alex-hunt-materialize]

Docs follow up for #35418

Motivation

Separate PR so we don't update the docs until we're ready to release.

Description

The first commit of this PR is just #35418, the second is the docs.

[github-actions]

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• Use imperative mood: "Fix X" not "Fixed X" or "Fixes X"
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[alex-hunt-materialize]

@kay-kim I'm keeping this as a draft so we don't accidentally merge it, but it is ready for review.

I may need to rebase if something comes up in the original PR, but I think the docs commit shouldn't change.

[kay-kim]

Thank you!!!