Update README.md

Author: carefree0910

README.md

@@ -2,8 +2,10 @@
 
 A Python ML package mainly for educational use.
 
-Implemented with numpy
+Implemented with **Numpy**
 
-Implemented tensorflow backend for NN & SVM
+Implemented **Tensorflow** backend for `NN` & `SVM`
+
+Implemented **PyTorch** backend for `NN`
 
 “文档”可以参见[知乎专栏](https://zhuanlan.zhihu.com/carefree0910-pyml)或[博客](https://carefree0910.github.io/MLBlog)