Update introduction.mdx

Author: simoninithomas

units/en/unit7/introduction.mdx

@@ -24,7 +24,13 @@ So today we’re going to **learn the basics of the fascinating topic of multi-a
 
 And the most exciting part is that, during this unit, you’re going to train your first agents in a multi-agents system: **a 2vs2 soccer team that needs to beat the opponent team**.
 
-And you’re going to participate in **AI vs. AI challenge** where your trained agent will compete against other classmates’ agents every day and be ranked on a [new leaderboard](https://huggingface.co/spaces/huggingface-projects/AIvsAI-SoccerTwos).
+## Course Maintenance Notice 🚧
+
+Please note that this **Deep Reinforcement Learning course is now in a low-maintenance state**. However, it **remains an excellent resource to learn both the theory and practical aspects of Deep Reinforcement Learning**.
+
+Keep in mind the following points:
+
+- *Unit 7 (AI vs AI)* : This feature is currently non-functional. However, you can still train your agent to play soccer and observe its performance. But the leaderboard for AI vs AI soccer was shut down.
 
 <figure>
 <img src="https://huggingface.co/datasets/huggingface-deep-rl-course/course-images/resolve/main/en/unit10/soccertwos.gif" alt="SoccerTwos"/>