chore(docs): remove Video Tutorial

Author: theniceangel

document/components/docs/zh-CN/quick-start.md

@@ -2,7 +2,6 @@
 
 - 新手教程项目：[cube-application-guide](https://github.com/cube-ui/cube-application-guide)
 - 遇到问题，先移步 [QA](https://github.com/cube-ui/question-answer/issues)
-- [视频教程](https://coding.imooc.com/class/74.html)
 
 ### 脚手架
 

document/components/home/en-US.vue

@@ -3,7 +3,6 @@
     <template slot="nav">
       <router-link to="/en-US/docs" class="tab"><span>Docs</span></router-link>
       <router-link to="/en-US/example" class="tab"><span>Example</span></router-link>
-      <a href="https://coding.imooc.com/class/74.html" target="_blank" class="tab">Video Tutorial</a>
     </template>
     <div slot="home">home</div>
   </home>

document/components/home/zh-CN.vue

@@ -3,7 +3,6 @@
     <template slot="nav">
       <router-link to="/zh-CN/docs" class="tab"><span>文档</span></router-link>
       <router-link to="/zh-CN/example" class="tab"><span>示例</span></router-link>
-      <a href="https://coding.imooc.com/class/74.html" target="_blank" class="tab">视频教程</a>
     </template>
     <div slot="home">home</div>
   </home>