What does the DOI identify?

[smrgeoinfo]

A DOI has been assigned "for the ten FREYA example notebooks" (doi:10.14454/fqq6-w751), but this URI resolves to a GitHub repository master branch, which is of course mutable. More notebooks are likely to be added, and existing notebooks are likely to change. Thus, what the DOI identifies is actually 'current master branch content in repository at https://github.com/datacite/pidgraph-notebooks-python'. Is this the intention?

Seems like it would be better to create a GitHub release and have the DOI resolve to that tagged version of the repository, so the content is immutable, and citations to that DOI made at different times would actually refer to the same thing.