docs: add QoS to README (#116)

Author: Timeless0911

README.md

@@ -79,6 +79,10 @@ This repo has adopted the ByteDance Open Source Code of Conduct. Please check [C
 
 Come and chat with us on [Discord](https://discord.gg/FQfm7VqU)! The Rstack team and users are active there, and we're always looking for contributions.
 
+## 🌟 Quality
+
+Rslib uses [Web Infra QoS](https://web-infra-qos.netlify.app?product=rslib&metrics=bundle-size) to observe the trend of key metrics, such as bundle size, compile speed and install size.
+
 ## 🙏 Credits
 
 Some of the implementations of Rslib have drawn inspiration from outstanding projects in the community. We would like to express our gratitude to them: