Update README.md

Author: carefree0910

README.md

@@ -4,8 +4,8 @@ A Python ML package mainly for educational use.
 
 Implemented with `Numpy`
 
-Implemented `Tensorflow` backend for **NN** & **SVM**
+Implemented `Tensorflow` backend for `NN` & `SVM`
 
-Implemented `PyTorch` backend for **NN**
+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)