OHDSI/TheBookOfOhdsi ? reverse-engineered prompt

Build me a polished online book site for The Book of OHDSI from this repo, using the chapter files that are already here.

I want it to feel like a real reference book, with a clean table of contents, easy chapter navigation, consistent styling, and working links between sections. The chapters should render nicely from the R markdown source, and the home page should clearly introduce what OHDSI is and help readers find where to begin.

Please make sure the book builds cleanly, the formatting works well for long technical content, tables, citations, and images, and the output is suitable for publishing online. If there are any missing pieces or modern setup details I should know about, look up current docs online if needed and wire it up the best way possible.

Also keep the existing content structure intact, and make it easy for contributors to update chapters later without breaking the site.