This resource from Gutenberg Times looks like it might be a great place to begin with Gutenberg development.
Development note: for the purposes of being able to remember gotchas when developing, I’ve added this development note with this bookmark.
While I’m not sure if this is a function of Gutenberg or not, I needed to manually input the information for the post name but not post excerpt, and I needed to manually input the site name. All of this applies when attempting to parse the information from the URL, which uses the “Parse This” portion of the Post Kinds plugin. This may mean something to look at specifically when migrating that plugin.