fix a broken link in AI agent demo

Author: duncanpo

examples/ai_agent/AddObservabilityToAIAgent.md

@@ -530,4 +530,4 @@ end
 
 # References
 <a id="M_4aeb"></a>
-\[1\] Shunyu Yao, Jeffrey Zhao, Dian Yu, Nan Du, Izhak Shafran, Karthik Narasimhan, and Yuan Cao. "ReAct: Synergizing Reasoning and Acting in Language Models". ArXiv, 10 March 2023. [https://doi.org/10.48550/arXiv.2210.03629.](https://doi.org/10.48550/arXiv.2210.03629.)
+\[1\] Shunyu Yao, Jeffrey Zhao, Dian Yu, Nan Du, Izhak Shafran, Karthik Narasimhan, and Yuan Cao. "ReAct: Synergizing Reasoning and Acting in Language Models". ArXiv, 10 March 2023. [https://doi.org/10.48550/arXiv.2210.03629](https://doi.org/10.48550/arXiv.2210.03629).