How was zanzibar.mdx created?

How did you create https://github.com/authzed/zanzibar-annotated/blob/main/content/zanzibar.mdx ? Is there some generator you used? I'd like to use it for annotating papers for public myself but would need to have a PDF->MDX workflow.

Thank you in advance!

P.S. Thank you for open-sourcing this repo, quite impressive work!