Clarify one-to-four message inference format

README.md

@@ -97,7 +97,7 @@ user:
 agent output:
 {agentOutput}
 
-return only the rewritten chat message or messages, separated by a blank line.
+return only the rewritten chat message or messages, separated by a blank line. use 1 to 4 messages total and never more than 4.
 ```
 
 Train only on `output` as the assistant completion. Gemma 4 natively supports system messages,