remove informative section about reification, collections, and containers from Semantics

[pfps]

https://www.w3.org/TR/rdf12-semantics/#non_semantics is non-normative. Its only semantics content is to point out some non-entailments.

But anyone who is confused as to how these IRIs don't work isn't going to get anything from the semantics bits of this section.

So I suggest that the section be removed. Any useful non-semantics content could be moved elsewhere.

[gkellogg]

I’m fine with removing and or moving non-normative sections, but it’s important that anchors remain in the document with a suitable pointer to the new location; the changes section would be fine.

[niklasl]

I agree and propose to move this to a new Note that I take an action to draft.