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.

.hyperhive/review-classifier.yml

@@ -95,3 +95,19 @@ classifications:
       such change makes the question not applicable.
     polarity: positive
     threshold: 65
+  - name: no-code-units-in-operator-docs
+    description: >-
+      Text added or changed under docs/1-getting-started/ or
+      docs/2-handbook/ names a specific code unit or describes how the code
+      works inside: a source path or file (`src/…`, `*.rs`, a module), a
+      function, struct, type or enum, a table or column, a queue subject or
+      wire field, or the mechanics of a protocol or migration. That detail
+      belongs in docs/4-implementation/, with a link from the operator
+      page. A command, flag, nix option, endpoint, service, systemd unit or
+      file an operator runs, sets, sees or edits is not a code unit, and
+      neither is the name of a crate or binary used as the service's name.
+      A diff that adds or changes nothing under those two directories makes
+      the question not applicable, and so do docs/4-implementation/,
+      docs/5-project/ and the options reference.
+    polarity: negative
+    threshold: 70

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",
             ]
         );
     }