Fix changelog style

CHANGELOG.zh-CN.md

@@ -13,6 +13,8 @@ timeline: true
 * 次版本号：每月发布一个带有新特性的向下兼容的版本。
 * 主版本号：含有破坏性更新和新特性，不在发布周期内。
 
+---
+
 ## 3.0.0
 
 `2017-12-04`

site/theme/static/markdown.less

@@ -299,26 +299,26 @@
     height: 80px;
     line-height: 80px;
   }
+}
 
-  // For Changelog
-  ul.ant-timeline {
-    li.ant-timeline-item {
-      list-style: none;
-      margin: 0;
-      padding: 0 0 30px;
-      .ant-timeline-item-content {
-        font-size: 14px;
-        padding-left: 32px;
-        position: relative;
-        top: -14px;
-        > h2 {
-          margin-top: 0;
-          padding-top: 0.5px;
-        }
+// For Changelog
+.markdown ul.ant-timeline {
+  li.ant-timeline-item {
+    list-style: none;
+    margin: 0;
+    padding: 0 0 30px;
+    .ant-timeline-item-content {
+      font-size: 14px;
+      padding-left: 32px;
+      position: relative;
+      top: -14px;
+      > h2 {
+        margin-top: 0;
+        padding-top: 2px;
       }
     }
-    li.ant-timeline-item:first-child {
-      margin-top: 40px;
-    }
+  }
+  li.ant-timeline-item:first-child {
+    margin-top: 40px;
   }
 }