fix: docs vue version

Author: huangjunfeng

docs/index.html

@@ -76,7 +76,7 @@
   </script>
   <!-- inject js file -->
   <script src="//unpkg.com/[email protected]/lib/docsify.min.js"></script>
-  <script src="//unpkg.com/vue/dist/vue.min.js"></script>
+  <script src="//unpkg.com/vue@2.6.14/dist/vue.min.js"></script>
   <script src="//unpkg.com/vuep/dist/vuep.min.js"></script>
   <script src="//unpkg.com/[email protected]/dist/echarts.min.js"></script>
   <script src="//unpkg.com/[email protected]/dist/echarts-wordcloud.js"></script>