Update README

Author: frankie567

README.md

@@ -8,10 +8,16 @@
     <em>Ready-to-use and customizable users management for FastAPI</em>
 </p>
 
+> [!NOTE]
+> **This project is now in maintenance mode.** While we'll continue to provide security updates and dependency maintenance, no new features will be added. We encourage you to explore the project and use it as-is, knowing it will remain stable and secure.
+>
+> We're currently working on a new Python authentication toolkit that will ultimately supersede FastAPI Users. Stay tuned for updates!
+
 [![build](https://github.com/fastapi-users/fastapi-users-db-beanie/workflows/Build/badge.svg)](https://github.com/fastapi-users/fastapi-users/actions)
 [![codecov](https://codecov.io/gh/fastapi-users/fastapi-users-db-beanie/branch/master/graph/badge.svg)](https://codecov.io/gh/fastapi-users/fastapi-users-db-beanie)
 [![PyPI version](https://badge.fury.io/py/fastapi-users-db-beanie.svg)](https://badge.fury.io/py/fastapi-users-db-beanie)
 [![Downloads](https://pepy.tech/badge/fastapi-users-db-beanie)](https://pepy.tech/project/fastapi-users-db-beanie)
+
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