jlucfarias/toth ? reverse-engineered prompt

Build me a cross platform command line app in Rust that turns a folder of Markdown files into a finished book.

I want it to let me define the book metadata, like title, author, description, and let me control the structure and presentation of the book so I can organize chapters the way I want. It should work well from the terminal, feel simple to automate, and run on Linux, macOS, and Windows.

Make the default experience easy, but let me customize things through a config file or command line options if needed. If you need to look up current Rust docs or best practices online, go ahead. I’d also like a clean README with example commands so someone can quickly understand how to build a book from Markdown and what files they need to provide.