It would be amazing to know who created or who is maintaining a document. Long term you could expand this into role based access, storing this information would also allow for segmenting certain authors to specific content.
MVP1: Store user profile who creates the document, store last_edited etc.
MVP2: Header/Footer for "Created by: John Doe" or "Last modified: Jane Doe" (additionally need check box in settings to add or remove depending on public/private implementation)
MVP3: Document security settings for restricting editing.