Include copyright in collapsible metadata

[dontcallmedom]

The current proposal hides a lot of data (some of it maybe too aggressively), but keeps the copyright line visible even though it is arguably not very useful. I would suggest including it in the collapsible part.

[wseltzer]

To be an effective "notice" of copyright, it needs to be visible to those seeing the document. Even when using a permissive license, we want to give notice of its status and terms.

[fantasai]

It would be fine if #145 is accepted, then? :)