add fallback langurages

docs/index.html

@@ -25,7 +25,8 @@
         placeholder: 'Search Documentation...',
         noData: 'We could not find any documents matching your search.',
         depth: 6
-      }
+      },
+      fallbackLanguages: ['zh-cn']
     }
   </script>
   <script src="//unpkg.com/docsify/lib/docsify.min.js"></script>