This revision has clarifications to the instructions which should make things clearer for those unfamiliar with OpenEmbedded. It also announces that [thud-draft] has been force-pushed and now contains recipes regenerated from the 2019-09-30 release of melodic and the 2019-09-19 release of crystal. In addition, the commits in the branch have been rearranged and squashed, and those that are morty-related have been dropped.
The document is here. Its change log is here. A “rich diff” of the changes made since the previous revision is here.