preview-guidance.html final editing issues

1. Is this intended to be a Committee Note? If so, SHOULD, SHOULD NOT, MUST, etc. should be lower case as a Committee Note is a non-standards track document and should not have conformance clauses?

2. This document is relatively short and is very similar to the non-normative material in dialogs-v3.html. Should we move this content into informative sections of the resource-preview.html document and use only one document?