add thanks

README.md

@@ -256,3 +256,5 @@ PaddleOCR文本识别算法的训练和使用请参考文档教程中[文本识
 
 ## 如何贡献代码
 我们非常欢迎你为PaddleOCR贡献代码，也十分感谢你的反馈。
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+- 非常感谢 [Khanh Tran](https://github.com/xxxpsyduck) 贡献了英文文档。

README_en.md

@@ -262,3 +262,5 @@ This project is released under <a href="https://github.com/PaddlePaddle/PaddleOC
 
 ## Contribution
 We welcome all the contributions to PaddleOCR and appreciate for your feedback very much.
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+- Many thanks to [Khanh Tran](https://github.com/xxxpsyduck) for contributing the English documentation.