chore: mark experimental

Author: KelvinChung2000

cmd2/annotated.py

@@ -1,5 +1,9 @@
 """Build argparse parsers from type-annotated function signatures.
 
+.. warning:: Experimental
+
+   This module is experimental and its behaviour may change in future releases.
+
 This module provides the :func:`with_annotated` decorator that inspects a
 command function's type hints and default values to automatically construct
 a ``Cmd2ArgumentParser``.  It also provides :class:`Argument` and

cmd2/decorators.py

@@ -355,6 +355,8 @@ def with_annotated(
 ) -> Any:
     """Decorate a ``do_*`` method to build its argparse parser from type annotations.
 
+    .. warning:: Experimental -- behaviour may change in future releases.
+
     :param func: the command function (when used without parentheses)
     :param ns_provider: optional callable returning a prepopulated argparse.Namespace
     :param preserve_quotes: if True, preserve quotes in arguments

docs/features/argument_processing.md

@@ -57,6 +57,11 @@ stores internally. A consequence is that parsers don't need to be unique across
 
 ## with_annotated decorator
 
+!!! warning "Experimental"
+
+    `@with_annotated` is experimental and its behaviour may change in future releases. If you
+    encounter issues, please report them and consider using `@with_argparser` as a stable alternative.
+
 The [@with_annotated][cmd2.decorators.with_annotated] decorator builds an argparse parser
 automatically from the decorated function's type annotations. No manual `add_argument()` calls are
 required.