Update default.html

Author: chatgpt-helper-tech

docs/_layouts/default.html

@@ -4,6 +4,8 @@
   <meta charset="UTF-8">
   <meta http-equiv="X-UA-Compatible" content="IE=edge">
   <meta name="viewport" content="width=device-width, initial-scale=1">
+  <meta name="robots" content="index, follow">
+
 
    <!-- 手动写title -->
     <title>{{ page.title | default: site.title }}</title>