project: add q4 roadmap news (#495)

Author: Xunzhuo

README.md

@@ -16,6 +16,7 @@
 
 *Latest News* 🔥
 
+- [2025/10/21] We announced the [2025 Q4 Roadmap: Journey to Iris](https://vllm-semantic-router.com/blog/q4-roadmap-iris) 📅.
 - [2025/10/16] We established the [vLLM Semantic Router Youtube Channel](https://www.youtube.com/@vLLMSemanticRouter) ✨.
 - [2025/10/15] We announced the [vLLM Semantic Router Dashboard](https://www.youtube.com/watch?v=E2IirN8PsFw) 🚀.
 - [2025/10/12] Our paper [When to Reason: Semantic Router for vLLM](https://arxiv.org/abs/2510.08731) accepted by NeurIPS 2025 MLForSys 🧠.