readme: add benchmark details

Author: krichprollsch

README.md

@@ -30,6 +30,7 @@ Fast web automation for AI agents, LLM training, scraping and testing:
 <img alt="Lightpanda benchmark graph" width=500px src="https://cdn.lightpanda.io/assets/images/benchmark_2025-02-19.png">
 </a>
 
+Puppeteer requesting 100 pages from a local website on a AWS EC2 m5.large instance.
 See [benchmark details](https://github.com/lightpanda-io/demo).
 
 ## Quick start