The README's opening paragraph called mfer/mf.proto the format specification
and linked to it. It now links docs/FORMAT.md, which is the specification, and
names mfer/mf.proto as the protobuf schema that document refers to for field
numbers and types. The link is relative, as the README's link to
REPO_POLICIES.md is, because docs/FORMAT.md is not on main yet.
Model: opus-5-5