use svg icon in introduce

components/tree/style/mixin.less

@@ -1,10 +1,6 @@
 @import "../../style/mixins/index";
 
 @tree-prefix-cls: ~"@{ant-prefix}-tree";
-@tree-default-open-icon: "\e606";
-@tree-showline-open-icon: "\e621";
-@tree-showline-close-icon: "\e645";
-@tree-doc-icon: "\e664";
 
 .antTreeSwitcherIcon(@type: "tree-default-open-icon") {
   .@{tree-prefix-cls}-switcher-icon {

docs/spec/introduce.en-US.md

@@ -26,13 +26,54 @@ We supply a series of design principles, practical patterns and high quality des
 
 [React](http://facebook.github.io/react/) is used to encapsulate a library of components which embody our design language. We welcome the community to implement [our design system](https://ant.design/docs/spec/introduce) in other front-end frameworks of their choice.
 
-- [Ant Design of React](/docs/react/introduce) (official implementation)
-- <div class="outside-link"><a href="http://ng.ant.design" target="_blank">NG-ZORRO - Ant Design of Angular</a></div>
-- <div class="outside-link"><a href="https://github.com/FE-Driver/vue-beauty" target="_blank">vue-beauty (vue)</a></div>
-- <div class="outside-link"><a href="https://github.com/priornix/antizer" target="_blank">antizer (ClojureScript)</a></div>
-- <div class="outside-link"><a href="https://github.com/idcos/antd-ember" target="_blank">antd-ember</a></div>
-- <div class="outside-link"><a href="https://github.com/zzuu666/antue" target="_blank">antue (vue)</a></div>
-- <div class="outside-link"><a href="https://github.com/vueComponent/ant-design" target="_blank">vue-antd-ui - Ant Design of Vue.js 2.5.0+</a></div>
+```__react
+import { Icon } from 'antd';
+
+const LinkIcon = () => (
+  <Icon type="export" className="outside-link-icon" />
+);
+
+const LinksList = () => (
+  <ul>
+    <li>
+      <a href="/docs/react/introduce" target="_blank">Ant Design of React</a>
+      (official implementation)
+    </li>
+    <li>
+      <a href="http://ng.ant.design" target="_blank">
+        NG-ZORRO - Ant Design of Angular<LinkIcon />
+      </a>
+    </li>
+    <li>
+      <a href="https://github.com/FE-Driver/vue-beauty" target="_blank">
+        vue-beauty (vue)<LinkIcon />
+      </a>
+    </li>
+    <li>
+      <a href="https://github.com/priornix/antizer" target="_blank">
+        antizer (ClojureScript)<LinkIcon />
+      </a>
+    </li>
+    <li>
+      <a href="https://github.com/idcos/antd-ember" target="_blank">
+        antd-ember<LinkIcon />
+      </a>
+    </li>
+    <li>
+      <a href="https://github.com/zzuu666/antue" target="_blank">
+        antue (vue)<LinkIcon />
+      </a>
+    </li>
+    <li>
+      <a href="https://github.com/vueComponent/ant-design" target="_blank">
+        vue-antd-ui - Ant Design of Vue.js 2.5.0+<LinkIcon />
+      </a>
+    </li>
+  </ul>
+);
+
+ReactDOM.render(<LinksList />, mountNode);
+```
 
 ## Who's using Ant Design
 

docs/spec/introduce.zh-CN.md

@@ -28,13 +28,54 @@ title: 介绍
 
 我们采用 [React](http://facebook.github.io/react/) 封装了一套 Ant Design 的组件库，也欢迎社区其他框架的实现版本。
 
-- [Ant Design of React](/docs/react/introduce)（官方实现）
-- <div class="outside-link"><a href="http://ng.ant.design" target="_blank">NG-ZORRO - Ant Design of Angular</a></div>
-- <div class="outside-link"><a href="https://github.com/FE-Driver/vue-beauty" target="_blank">vue-beauty (vue)</a></div>
-- <div class="outside-link"><a href="https://github.com/priornix/antizer" target="_blank">antizer (ClojureScript)</a></div>
-- <div class="outside-link"><a href="https://github.com/idcos/antd-ember" target="_blank">antd-ember</a></div>
-- <div class="outside-link"><a href="https://github.com/zzuu666/antue" target="_blank">antue (vue)</a></div>
-- <div class="outside-link"><a href="https://github.com/vueComponent/ant-design" target="_blank">vue-antd-ui - Ant Design of Vue.js 2.5.0+</a></div>
+```__react
+import { Icon } from 'antd';
+
+const LinkIcon = () => (
+  <Icon type="export" className="outside-link-icon" />
+);
+
+const LinksList = () => (
+  <ul>
+    <li>
+      <a href="/docs/react/introduce" target="_blank">Ant Design of React</a>
+      （官方实现）
+    </li>
+    <li>
+      <a href="http://ng.ant.design" target="_blank">
+        NG-ZORRO - Ant Design of Angular<LinkIcon />
+      </a>
+    </li>
+    <li>
+      <a href="https://github.com/FE-Driver/vue-beauty" target="_blank">
+        vue-beauty (vue)<LinkIcon />
+      </a>
+    </li>
+    <li>
+      <a href="https://github.com/priornix/antizer" target="_blank">
+        antizer (ClojureScript)<LinkIcon />
+      </a>
+    </li>
+    <li>
+      <a href="https://github.com/idcos/antd-ember" target="_blank">
+        antd-ember<LinkIcon />
+      </a>
+    </li>
+    <li>
+      <a href="https://github.com/zzuu666/antue" target="_blank">
+        antue (vue)<LinkIcon />
+      </a>
+    </li>
+    <li>
+      <a href="https://github.com/vueComponent/ant-design" target="_blank">
+        vue-antd-ui - Ant Design of Vue.js 2.5.0+<LinkIcon />
+      </a>
+    </li>
+  </ul>
+);
+
+ReactDOM.render(<LinksList />, mountNode);
+```
 
 ## 谁在使用
 

site/theme/static/common.less

@@ -90,9 +90,7 @@ a {
   display: inline-block;
 }
 
-.outside-link:after {
-  content: '\e691';
-  font-family: 'anticon';
+.outside-link-icon {
   margin-left: 5px;
   font-size: 12px;
   color: #aaa;