add cli docs generator

pkgs/clan-cli/clan_cli/__init__.py

@@ -79,13 +79,17 @@ def create_parser(prog: str | None = None) -> argparse.ArgumentParser:
         "--flake",
         help="path to the flake where the clan resides in, can be a remote flake or local, can be set through the [CLAN_DIR] environment variable",
         default=get_clan_flake_toplevel_or_env(),
+        metavar="PATH",
         type=flake_path,
+        epilog="Default is dynamically determined based on the current directory.",
     )
 
     subparsers = parser.add_subparsers()
 
     parser_backups = subparsers.add_parser(
-        "backups", help="manage backups of clan machines"
+        "backups",
+        help="manage backups of clan machines",
+        description="manage backups of clan machines",
     )
     backups.register_parser(parser_backups)
 

pkgs/clan-cli/clan_cli/machines/update.py

@@ -182,9 +182,10 @@ def register_update_parser(parser: argparse.ArgumentParser) -> None:
     parser.add_argument(
         "machines",
         type=str,
-        help="machine to update. if empty, update all machines",
         nargs="*",
         default=[],
+        metavar="MACHINE",
+        help="machine to update. If no machine is specified, all machines will be updated.",
     )
     parser.add_argument(
         "--target-host",