update `.releaserc` to support more conventional commit types

[brian-smith-tcril]

Raising this issue because a refactor: commit didn't trigger a semantic release.

I figure it's worth discussing what commit types are worth adding, so here's a place for that!

[arbrandes]

We'd likely want to write up an ADR (possibly as part of OEP-47 and proposed this there. I'm sure there'll be different points of view.