hackmdio/codimd ? reverse-engineered prompt

Build me a self hosted web app like CodiMD where people can create markdown notes and edit them together in real time. I want it to feel simple and fast, with a clean editor, live updates as multiple people type, and a way to share notes by link. It should work well in the browser on desktop and mobile, and users should be able to keep control of their own content.

Please make it ready to run as a normal open source project, with a clear setup flow, sensible defaults, and a place for configuration so I can deploy it myself. If you need to check current docs or best practices while building it, go ahead and look them up online. I do not need extra fancy features, just the core experience of collaborative markdown notes that is reliable and easy to host for a team or community.