chore: update screenshot (#1144)

Author: QingWei-Li

README.md

@@ -3,7 +3,7 @@
 > Vue.js component loader for [Webpack](https://webpack.js.org/).
 
 <p align="center">
-  <img width="809px" src="https://raw.githubusercontent.com/vuejs/vue-syntax-highlight/master/samples/screenshot.png">
+  <img width="809px" src="https://raw.githubusercontent.com/vuejs/vue-syntax-highlight/new/samples/screenshot.png">
 </p>
 
 The best way to get started is with [vue-cli](https://github.com/vuejs/vue-cli):