We know. We are doing our best to update the docs and website, we will publish something better soon. In the meantime you can have a look at our blogs (e.g. http://blog.athico.com/) and our examples https://github.com/kiegroup/kogito-examples

this deep dive is also a nice overview of the project (also yay I am there) https://www.youtube.com/watch?v=KBkX6v57Jbo