docs: update readme with npm packages

README.md

@@ -6,6 +6,9 @@
 
 <p>
   <a href="https://discord.gg/FQfm7VqU"><img src="https://img.shields.io/badge/chat-discord-blue?style=flat-square&logo=discord&colorA=564341&colorB=F8F5FF" alt="Discord channel" /></a>
+  <a href="https://npmjs.com/package/@rslib/core?activeTab=readme"><img src="https://img.shields.io/npm/v/@rslib/core?style=flat-square&colorA=564341&colorB=EDED91" alt="npm version" /></a>
+  <a href="https://npmcharts.com/compare/@rslib/core?minimal=true"><img src="https://img.shields.io/npm/dm/@rslib/core.svg?style=flat-square&colorA=564341&colorB=EDED91" alt="downloads" /></a>
+  <a href="https://nodejs.org/en/about/previous-releases"><img src="https://img.shields.io/node/v/@rslib/core.svg?style=flat-square&colorA=564341&colorB=EDED91" alt="node version"></a>
   <a href="https://github.com/web-infra-dev/rslib/blob/main/LICENSE"><img src="https://img.shields.io/badge/License-MIT-blue.svg?style=flat-square&colorA=564341&colorB=F8F5FF" alt="license" /></a>
 </p>