Update README.md

Author: Asher-1

README.md

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 [github 链接](https://github.com/PegasusWang/python_data_structures_and_algorithms)
 
 [readthedoc 电子书下载](http://python-data-structures-and-algorithms.readthedocs.io/zh/latest/)
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 [本人github.io电子书地址](https://Asher-1.github.io/python_data_structures_and_algorithms/)
 
 [《开源一个 Python 算法和数据结构中文教程[视频]》](https://zhuanlan.zhihu.com/p/36038003)  视频讲解示例