Fix typo in examples/run_squad.py

Rul -> Run

examples/run_squad.py

@@ -586,7 +586,7 @@ def main():
     parser.add_argument("--do_train", action="store_true", help="Whether to run training.")
     parser.add_argument("--do_eval", action="store_true", help="Whether to run eval on the dev set.")
     parser.add_argument(
-        "--evaluate_during_training", action="store_true", help="Rul evaluation during training at each logging step."
+        "--evaluate_during_training", action="store_true", help="Run evaluation during training at each logging step."
     )
     parser.add_argument(
         "--do_lower_case", action="store_true", help="Set this flag if you are using an uncased model."