Add npm downloads badge to README

Author: hidai25

README.md

@@ -15,6 +15,7 @@
 
 [![PyPI version](https://img.shields.io/pypi/v/evalview.svg)](https://pypi.org/project/evalview/)
 [![PyPI downloads](https://img.shields.io/pypi/dm/evalview.svg)](https://pypi.org/project/evalview/)
+[![npm downloads](https://img.shields.io/npm/dm/@evalview/node.svg)](https://www.npmjs.com/package/@evalview/node)
 [![GitHub Action](https://img.shields.io/badge/GitHub%20Action-Marketplace-blue?logo=github)](https://github.com/marketplace/actions/evalview-ai-agent-testing)
 
 <p align="center">