docs: 更新文档地址

src/views/demo/playground/frame/d2-doc/index.vue

@@ -1,3 +1,3 @@
 <template>
-  <d2-container-frame src="https://d2.pub/zh/doc/d2-admin"/>
+  <d2-container-frame src="https://d2.pub/doc/d2-admin"/>
 </template>

src/views/demo/playground/locales/index.vue

@@ -17,6 +17,6 @@
     <d2-link-btn
       slot="footer"
       title="文档"
-      link="https://d2.pub/zh/doc/d2-admin/locales"/>
+      link="https://d2.pub/doc/d2-admin/locales"/>
   </d2-container>
 </template>

src/views/system/index/components/d2-help/index.vue

@@ -14,7 +14,7 @@
           这里有一些参考资料
         </h2>
         <el-button-group>
-          <el-button @click="$open('https://d2.pub/zh/doc/d2-admin')">
+          <el-button @click="$open('https://d2.pub/doc/d2-admin')">
             <d2-icon name="book" class="d2-mr-5"/>
             文档
           </el-button>

src/views/system/index/index.vue

@@ -5,7 +5,7 @@
       <template slot="footer">
         <div class="btn-group">
           <span class="btn-group__btn" @click="$open('https://github.com/d2-projects')">开源组织</span> |
-          <span class="btn-group__btn" @click="$open('https://d2.pub/zh/doc/d2-admin')">文档</span> |
+          <span class="btn-group__btn" @click="$open('https://d2.pub/doc/d2-admin')">文档</span> |
           <span class="btn-group__btn" @click="$open('https://github.com/d2-projects/d2-admin-start-kit')">简化版</span> |
           <span class="btn-group__btn" @click="$open('https://juejin.im/user/57a48b632e958a006691b946/posts')">掘金</span> |
           <el-popover :width="150" trigger="hover">