Add code comment re control types

tcharding · tcharding · commit 8fcceff0f96f · 2024-10-16T08:15:44.000+11:00
diff --git a/json/src/model/control.rs b/json/src/model/control.rs
@@ -4,3 +4,5 @@
 //!
 //! These structs model the types returned by the JSON-RPC API but have concrete types
 //! and are not specific to a specific version of Bitcoin Core.
+
+// Control types currently have no need for model equivalents.
