Add github button

scripts/home.js

@@ -74,7 +74,10 @@ module.exports = function() {
               <h2 key="h2">ANT <p>DESIGN</p></h2>
               <p key="content">一个 UI 设计语言</p>
               <span className="line" key="line"/>
-              <a key="button" href="/docs/spec/introduce"><Icon type="smile-circle"/>开始探索</a>
+              <div className="start-button">
+                <a key="button" href="/docs/spec/introduce"><Icon type="smile-circle"/>开始探索</a>
+              </div>
+              <iframe src="https://ghbtns.com/github-btn.html?user=ant-design&repo=ant-design&type=star&count=true" frameBorder="0" scrolling="0" width="95px" height="20px" />
             </QueueAnim>
             <TweenOne className='down' vars={[{opacity: 1},{y: 10, duration: 800, yoyo: true, repeat: -1}]}>
               <Icon type="down"/>

site/templates/home.html

@@ -62,7 +62,7 @@
   .banner-text-wrapper {
     position: absolute;
     left: 10%;
-    top: 58%;
+    top: 55%;
     color: #fff;
     text-align: right;
   }
@@ -105,26 +105,40 @@
   }
 
   .banner-text-wrapper > p {
-    margin: 10px auto 30px;
+    margin: 10px auto 24px;
     font-size: 16px;
   }
 
-  .banner-text-wrapper a {
-    float: right;
+  .banner-text-wrapper .start-button {
+    margin-bottom: 24px;
+  }
+
+  .banner-text-wrapper .start-button a {
     width: 155px;
     height: 45px;
     border-radius: 6px;
-    border: 1px solid #00AAEE;
-    color: #00AAEE;
+    border: 1px solid #2db7f5;
+    color: #2db7f5;
     font-size: 18px;
     background: transparent;
     transition: box-shadow .45s ease-out;
     text-align: center;
     line-height: 42px;
+    display: inline-block;
+  }
+
+  .banner-text-wrapper iframe {
+    border: 0;
+    opacity: 0.8;
+    transition: opacity 0.3s ease;
+  }
+
+  .banner-text-wrapper iframe:hover {
+    opacity: 1;
   }
 
   .banner-text-wrapper a:hover {
-    box-shadow: 0 0 10px #00AAEE;
+    box-shadow: 0 0 10px #2db7f5;
   }
 
   .banner-text-wrapper a span {