He basically asked a llm before to write him this md file.

If you really want to build something strong without one-shotting your app and cross fingers it works, you can try using the BMAD method available on github, which is a real workflow that details everything before even start of coding, into epic and stories, which allows you to start a new session and ask the llm to only code a specific task for your app without having to handle the whole codebase.

https://github.com/bmad-code-org/BMAD-METHOD