review classifier: operator docs name no code units

A negative rule for docs/1-getting-started and docs/2-handbook: text that
names a source path, function, type, table, queue subject or wire field, or
describes how the code works inside, belongs in docs/4-implementation. The
rules-file test lists the new name.

swarm-controller/src/review_classifier.rs

@@ -1417,6 +1417,7 @@ classifications:
                 "docs-updated",
                 "one-purpose",
                 "message-claims-match-diff",
+                "no-code-units-in-operator-docs",
             ]
         );
     }