Merge branch 'git' into 'master'

Git

See merge request codechina/operation-work!116

explore/index.yml

 banner:
-- link: https://cccst.org.cn/subpage/osis?utm_source=codechina
-  url: https://codechina.csdn.net/codechina/operation-work/uploads/95d29efa9688e83fc57e81951998c03f/cccst.jpg
+- link: https://bbs.csdn.net/topics/603483762
+  url: https://gitcode.net/codechina/operation-work/uploads/b616e85feaa9b81adc4ffad53a3b9d29/banner.png
 groups:
 - csdn
 - oceanbase
@@ -19,7 +19,7 @@ groups:
 - zongzhige
 learning_banner:
 - link: /courses 
-  url: https://codechina.csdn.net/codechina/operation-work/uploads/38be577289ba8800a9caa233416cd4b6/1920x480_1_.png
+  url: https://gitcode.net/codechina/operation-work/uploads/601713360feb9ec41dd5b5f59bef4569/lab.jpg
 projects:
 - hihell/python120 
 - opendilab/DI-engine