Update README.md

Author: shinny-xuyida

README.md

@@ -86,7 +86,7 @@ Documentation
 
 Gui
 -------------------------------------------------
-TqSdk本身自带的web_gui功能，简单一行参数即可支持调用图形化界面，详情参加[web_gui](https://doc.shinnytech.com/pysdk/latest/usage/web_gui.html) 
+TqSdk本身自带的web_gui功能，简单一行参数即可支持调用图形化界面，详情参考[web_gui](https://doc.shinnytech.com/pysdk/latest/usage/web_gui.html) 
 <img alt="TqSdk web_gui" src="https://raw.githubusercontent.com/shinnytech/tqsdk-python/master/doc/images/web_gui_backtest.png">
 
 About us