[Improvement] Model Provisions 0.x transition to "finished"

[shanecoughlan]

This is an open issue for:
https://github.com/OpenChain-Project/Reference-Material/blob/master/Adoption-Preparation/Model-Provisions/openchain-standards-model-provisions.0.5.md

Perhaps we should include a notice along these lines at the start of the document when we stop the primary drafting and move into long-term mode:

"This document is a living document. It is intended to act as a reference with examples. The material inside the document will be updated on a rolling basis by our community."