Release 2.1.0 documents code-metrics.yml at @v1 and defaults tools-ref to
v1, but the workflow and its scripts exist only from v2.1.0. MIL-011
plans the fix (a patch release 2.1.1), the test that would have caught
it, the guide and wiki corrections, and the removal of the workaround
from the framework Badges page. Proposed; no code changes yet.
