ooooo transclusion !
I built a very rough md prototype called hypermarkdown when I was first learning node (brace for beginner code!). It would totally be possible here in scuttlebutt. We actually ended up using transculsion to write learning resources for Enspiral Dev Academy, using some rough transclusion features in gitbook. These are actually what make the current http://modules.scuttlebutt.nz/ so easy to build. That only lets you pull whole markdown files though. Even this is incredibly powerful. This plus "give me the latest version/ a specific version" would mean no more having to build static sites repeatedly to keep things up to date