basecamp/writebook ? reverse-engineered prompt

Build me a simple web app called Writebook that lets people publish their own books online without needing a publisher.

I want authors to be able to write content in Markdown, organize a book into title pages, chapters, and picture pages, then publish it either privately or publicly. Public books should be searchable, and the whole thing should feel easy to use for someone who just wants to write and share a book.

Make it ready to run locally for development and also easy to deploy with Docker, since I want the app to be packaged that way. If you need to check current docs for any Ruby or Rails setup details, go ahead and look them up online. Keep the interface clean and focused on writing and publishing, not on extra fluff.