Update README.md

Author: dragen1860

README.md

@@ -3,7 +3,7 @@
 **课程链接:** https://study.163.com/provider/480000001847407/index.htm?share=2&shareId=480000001847407
 
 
-<img src="res/cover.png" alt="drawing" width="300" align="middle"/>
+<img src="res/cover.png" alt="cover" width="300" style="float: right;">
 
 **课程大纲:**
 ![课程介绍](res/outline.png)