Update documentation to require Preview

It would also help to add validation to the node type form that shows an error if Same Page Preview is enabled, but Preview isn't.

Agreed. I'll add that into the documentation. I would consider an overhaul of the documentation but for now I'll just add a one-liner.

@DieterHolvoet MR created please review.

Maybe you could also mention that this needs to be enabled for every node type separately?

It shouldn't be the case that you need to enable Same Page Preview for each content type separately. The content type settings are intended to be an opt-out strategy.

Okay, in that case all good.

Automatically closed - issue fixed for 2 weeks with no activity.