Documentation for @contentful/rich-text-types?

I was able to use the demo code from this tutorial, but it appears I would need to go into the plugin code itself if I wanted to know what other MARKS, BLOCKS, or INLINES, properties I could configure. Perhaps I’m missing something, but the repo just has a small blurb without any instructions on usage and I’m not a level 9000 l337 hax0r so I’m stuck just reverse engineering an example that might not work if Gatsby updates.