Transformers cli clean command (#37657)

* transformers-cli -> transformers

* Chat command works with positional argument

* update doc references to transformers-cli

* doc headers

* deepspeed

---------

Co-authored-by: Joao Gante <joao@huggingface.co>

tests/utils/test_cli.py

@@ -23,7 +23,7 @@ from transformers.testing_utils import CaptureStd, require_torch
 class CLITest(unittest.TestCase):
     @patch("sys.argv", ["fakeprogrampath", "env"])
     def test_cli_env(self):
-        # test transformers-cli env
+        # test transformers env
         import transformers.commands.transformers_cli
 
         with CaptureStd() as cs: