[skip ci] Add comment of main file on benchmark (#9051)

Signed-off-by: Nwangting0128 <ting.wang@zilliz.com>

tests/benchmark/milvus_benchmark/main.py

@@ -125,6 +125,7 @@ def run_suite(run_type, suite, env_mode, env_params, timeout=None):
 
 
 def main():
+    # Parse the incoming parameters and run the corresponding test cases
     arg_parser = argparse.ArgumentParser(
         formatter_class=argparse.ArgumentDefaultsHelpFormatter)
     # helm mode with scheduler