[larsoner]

1. News was very out of date, add entries for other releases
2. Add agentic guidance, basically: 1) interactions should be between humans, 2) code changes should be short / minimal, and 3) what the repo is about. It is adapted from MNE-Python, where similar guidance has been working reasonably well for the last ~6mo or so.

Changes drafted by Claude Opus 5.5 and reviewed by me.