fix: Deprecation notice

README.md

@@ -2,9 +2,15 @@
   <img src="https://github.com/box/sdks/blob/master/images/box-dev-logo.png" alt= “box-dev-logo” width="30%" height="50%">
 </p>
 
+# Deprecation notice
+
+This version of the Box Python SDK is under maintenance mode, and will be deprecated soon, only critical security updates and bug fixes will be provided. We recommend using the new version Box Python SDK, which can be found at [box/box-python-sdk-gen](https://github.com/box/box-python-sdk-gen)
+
+From Box Python SDK v3.x, you can find the migration guide [here](https://github.com/box/box-python-sdk-gen/blob/main/migration-guide.md). If you have any questions, please create an issue in the new repository or reach out to [Box Developer Support](https://developer.box.com/support/).
+
 # Box Python SDK
 
-[![image](http://opensource.box.com/badges/active.svg)](http://opensource.box.com/badges)
+[![image](http://opensource.box.com/badges/stable.svg)](http://opensource.box.com/badges)
 [![Documentation Status](https://readthedocs.org/projects/box-python-sdk/badge/?version=latest)](http://box-python-sdk.readthedocs.org/en/latest)
 [![image](https://github.com/box/box-python-sdk/workflows/build/badge.svg)](https://github.com/box/box-python-sdk/actions)
 [![image](https://img.shields.io/pypi/v/boxsdk.svg)](https://pypi.python.org/pypi/boxsdk)

boxsdk/client/client.py

@@ -2,6 +2,7 @@
 import json
 from datetime import datetime
 from typing import TYPE_CHECKING, Optional, Iterable, Union, Any, IO
+from warnings import warn
 
 from ..auth.oauth2 import TokenResponse
 from ..session.session import Session, AuthorizedSession
@@ -74,6 +75,7 @@ def __init__(self, oauth: 'OAuth2', session: Session = None):
             The session object to use. If None is provided then an instance of :class:`AuthorizedSession` will be used.
         """
         super().__init__()
+        warn('Package \'boxsdk\' is going to be deprecated soon. Please use \'box-sdk-gen\' instead.', DeprecationWarning)
         self._oauth = oauth
         if session is not None:
             self._session = session