Add manual.yml to build mdBook documentation

[kurosakishigure]

Page Link

https://github.com/kurosakishigure/katharsis

What is the documentation issue?

We need to set up a GitHub/Cloudflare Pages site to host the online documentation, making it easier for users to access and reference the documentation.

Is there any context that might help us understand?

We can refer to: manual.yml and manual

[kurosakishigure]

Should we consider adopting Next.js's approach to display documentation for different versions on our documentation page🤔: