doc: Update README.md

Author: jaywcjlove

core/README.md

@@ -6,7 +6,7 @@
 
 # react-codemirror
 
-[![jsdelivr CDN](https://data.jsdelivr.com/v1/package/npm/@uiw/react-codemirror/badge?style=rounded)](https://www.jsdelivr.com/package/npm/@uiw/react-codemirror)
+[![jsdelivr CDN](https://data.jsdelivr.com/v1/package/npm/@uiw/react-codemirror/badge)](https://www.jsdelivr.com/package/npm/@uiw/react-codemirror)
 [![NPM Downloads](https://img.shields.io/npm/dm/@uiw/react-codemirror.svg?style=flat)](https://www.npmjs.com/package/@uiw/react-codemirror)
 [![Build & Deploy](https://github.com/uiwjs/react-codemirror/workflows/Build%20&%20Deploy/badge.svg)](https://github.com/uiwjs/react-codemirror/actions)
 [![Open in unpkg](https://img.shields.io/badge/Open%20in-unpkg-blue)](https://uiwjs.github.io/npm-unpkg/#/pkg/@uiw/react-codemirror/file/README.md)