Yes, the .md's are in their own repo, locally. The entire UI is a layer on top of that repo. The UI has some underlying mechanisms that abstract the git operations away from the user, but that doesn't stop a power user from jumping in the shell and accessing the repo directly.
The "magic" starts when Sig contributes to another, remote repo - a central knowledge base that all teammates' local Sig can pull from, and contribute toward.
The "magic" starts when Sig contributes to another, remote repo - a central knowledge base that all teammates' local Sig can pull from, and contribute toward.