Adding more information in help parser on train_file and validation_file (#25324)

chorse: adding new doc on train and val

examples/pytorch/language-modeling/run_clm_no_trainer.py

@@ -82,10 +82,10 @@ def parse_args():
         help="The configuration name of the dataset to use (via the datasets library).",
     )
     parser.add_argument(
-        "--train_file", type=str, default=None, help="A csv or a json file containing the training data."
+        "--train_file", type=str, default=None, help="A csv, txt or a json file containing the training data."
     )
     parser.add_argument(
-        "--validation_file", type=str, default=None, help="A csv or a json file containing the validation data."
+        "--validation_file", type=str, default=None, help="A csv, txt or a json file containing the validation data."
     )
     parser.add_argument(
         "--validation_split_percentage",