We should put any documentation that go into Haddock should do into Haddock. This just serves to provide a sort of high-level overview tying everything together (perhaps this also belongs as documentation for the Darcs.Patch module?).
Darcs 1 patches look like this:
Named patch | +-- Patch (Merger, PP, etc) | +-- Patch (nesting) | +-- Prim
Darcs 2 patches look like this:
Named patch | +-- RealPatch (Conflictor, Duplicate, etc) | +-- Non | | | +-- RealPatch (nesting) | | | +-- Prim | +-- Prim