update DQN

codes/dqn/README.md

@@ -1,3 +1,8 @@
+## 思路
+
+见[我的博客](https://blog.csdn.net/JohnJim0/article/details/109557173)
+## 环境
+
 python 3.7.9
 
 pytorch 1.6.0
@@ -6,6 +11,7 @@ tensorboard 2.3.0
 
 torchvision 0.7.0 
 
+## 使用
 
 train: 
 
@@ -18,7 +24,12 @@ eval:
 ```python
 python main.py --train 0 
 ```
-
+可视化：
 ```python
 tensorboard --logdir logs 
-```
+```
+
+## Torch知识
+
+[with torch.no_grad()](https://www.jianshu.com/p/1cea017f5d11)
+