Config Doc - Commit somewhere the model and the output

[gsmet]

When working on the extension annotation processor, it can be hard to check that a change doesn't create unwanted side effects.
Or to easily spot that a change does what is intended.

I think we should commit somewhere the generated model and the output.
Or maybe have a way to centralize them easily and compare.

In any case, I don't think we should commit it to the main repo or it will get out of hands.

/cc @cescoffier and @radcortez for discussion when they're back.

[quarkus-bot]

/cc @radcortez (config)