We should document how to write the changelog

[sigurdm]

It would be nice to be able to reliably parse CHANGELOG.md files. We could then

• give better error messages
• merge the changelog into the "versions" tab. (Merge the changelog into the "versions" tab. pub-dev#8943)
• nudge people to write better changelogs by scoring fewer points if it does not parse well. (Nudge people to write better changelogs by scoring fewer points if it does not parse well. #1475)
• ...

[sigurdm]

This seems doable now that we have better parsing of changelogs on pub.dev

[sigurdm]

We could keep recommendations to a minimum, just caring about the parts of the changelog we recognize.

https://keepachangelog.com/en/1.1.0/ has good recommendations, but seems perhaps overly prescriptive. We could recommend some subset perhaps.