rename

Author: JenniferWang

apps/trainer/main.py renamed to apps/rl_trainer/main.py

@@ -4,7 +4,7 @@
 # This source code is licensed under the BSD-style license found in the
 # LICENSE file in the root directory of this source tree.
 
-# Usage: python -m apps.trainer.main --config apps/grpo/qwen3_32b.yaml
+# Usage: python -m apps.rl_trainer.main --config apps/grpo/qwen3_32b.yaml
 
 import asyncio