Update README_EN.md

Author: CarGuo

README_EN.md

@@ -25,7 +25,7 @@ With the use and feedback of the project, will user experience and function opti
 * ### [Flutter 完整开发实战详解(三、打包填坑篇)](https://juejin.im/entry/5b6fd5ee6fb9a009d36a4104 )
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 * ### [Flutter 完整开发实战详解(五、深入探索)](https://juejin.im/post/5bc450dff265da0a951f032b )
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+* ### [Flutter 完整开发实战详解(六、 深入Widget原理)](https://juejin.im/post/5c7e853151882549664b0543 )