feat: 添加learning-lab的banner图

explore/index.yml

@@ -3,6 +3,9 @@ banner:
 #    link: 'https://codechina.csdn.net/lives'
   - url: 'https://codechina.csdn.net/codechina/operation-work/uploads/31e019e8f163e57fd0b357c99b0ba92e/1920x492.png'
     link: 'https://codechina.csdn.net/lives'
+learning_banner: 
+  - url: 'https://codechina.csdn.net/codechina/operation-work/uploads/38be577289ba8800a9caa233416cd4b6/1920x480_1_.png'
+    link: 'https://codechina.csdn.net/courses'
 trending_words: 
 #  - content: '@DJ_Dave 小姐姐同款打碟软件'
 #    link: 'https://codechina.csdn.net/mirrors/sonic-pi-net/sonic-pi'