I don’t think there’s a special format but it could simply be a Markdown file with these sections:
-
Abstract: in 2-3 lines, what the project is about, why it’s needed.
-
Specifications: as much details as possible about the feature. I think your post above is pretty much it.
-
External links: a link to the discussion here, or any other link you can find related to the feature. As I understand, they want to see that there’s interest around the feature and discussions happening so that would be the point of this section.
Perhaps @PackElend has additional suggestions about this.