CLI: Hide json-keymap subcommand, as it's been deprecated.

lib/python/qmk/cli/json/keymap.py

@@ -8,7 +8,7 @@ from milc import cli
 @cli.argument('-o', '--output', arg_only=True, type=Path, help='File to write to')
 @cli.argument('-q', '--quiet', arg_only=True, action='store_true', help="Quiet mode, only output error messages")
 @cli.argument('filename', arg_only=True, help='Configurator JSON file')
-@cli.subcommand('Creates a keymap.c from a QMK Configurator export.')
+@cli.subcommand('Creates a keymap.c from a QMK Configurator export.', hidden=True)
 def json_keymap(cli):
     """Renamed to `qmk json2c`.
     """