Support -h help option for user friendliness / best practices (#700)

Thank you @GHPS!

Author: tony

tests/test_cli.py

@@ -761,6 +761,18 @@ def test_import(cli_args, monkeypatch):
     assert 'tmuxinator' in result.output
     assert 'teamocil' in result.output
 
+@pytest.mark.parametrize(
+    "cli_args",
+    [
+        (['--help']),
+        (['-h']),
+    ],
+)
+def test_help(cli_args, monkeypatch):
+    runner = CliRunner()
+
+    result = runner.invoke(cli.cli, cli_args)
+    assert 'Usage: cli [OPTIONS] COMMAND [ARGS]...' in result.output
 
 @pytest.mark.parametrize(
     "cli_args,inputs",

tmuxp/cli.py

@@ -749,7 +749,7 @@ def load_workspace(
     return _setup_plugins(builder)
 
 
-@click.group(context_settings={'obj': {}})
+@click.group(context_settings={'obj': {}, 'help_option_names':['-h', '--help']})
 @click.version_option(__version__, '-V', '--version', message='%(prog)s %(version)s')
 @click.option(
     '--log-level',