What is the expected enhancement?

Right now when it's almost release time we have to go through the changelog file parse the intent of the small one line description that a patch author put there (which can often be difficult) and transform that into a human readable and friendly release note document. (see for example: #211 or #1456). This manual process puts the burden of writing all the documentation on a single person or small group of people and puts pressure to get this done before the release.

Instead it would be better to do this incrementally as we add features, or make changes that warrant a release note. To do this we can leverage the reno project: https://docs.openstack.org/reno/latest/ this enables us to include a small yaml file with all the release documentation needed in a PR split up by sections. Then at release time reno will automatically assemble all those independent files into a single release notes document for a release. Using this means the burden for writing release notes is shared among all contributors to terra. When a patch author pushes a user facing change we should require that they write a detailed release note explaining the changes.

For an example of the output you can take a look at: https://docs.openstack.org/releasenotes/nova/stein.html