This document is meant to be a record of how we think about Git
submodules (and not a _current_ implementation of submodules). We will
fill it out incrementally as we get a clearer idea of what we want
submodules to look like.
As an initial version, I started with (IMO) the least controversial
points:
- We want to support most workflows Git submodules users are accustomed
to.
- A roadmap that allows us to incrementally roll out Git submodule
functionality (instead of having to boil the ocean).