tweak some styles

src/components/DescriptionList/demo/basic.md

@@ -11,7 +11,7 @@ import DescriptionList from 'ant-design-pro/lib/DescriptionList';
 const { Description } = DescriptionList;
 
 ReactDOM.render(
-  <DescriptionList title="title">
+  <DescriptionList size="large" title="title">
     <Description term="Firefox">
       A free, open source, cross-platform,
       graphical web browser developed by the

src/components/DescriptionList/demo/vertical.md

@@ -11,7 +11,7 @@ import DescriptionList from 'ant-design-pro/lib/DescriptionList';
 const { Description } = DescriptionList;
 
 ReactDOM.render(
-  <DescriptionList title="title" layout="vertical">
+  <DescriptionList size="large" title="title" layout="vertical">
     <Description term="Firefox">
       A free, open source, cross-platform,
       graphical web browser developed by the

src/components/DescriptionList/index.md

@@ -17,6 +17,7 @@ order: 4
 | col       | 指定信息最多分几列展示，最终一行几列由 col 配置结合[响应式规则](/components/DescriptionList#响应式规则)决定          | number(0 < col <= 4)  | 3 |
 | title     | 列表标题                                 | ReactNode  | - |
 | gutter    | 列表项间距，单位为 `px`                    | number  | 32 |
+| size     | 列表型号，可以设置为 `large` `small`        | string  | - |
 
 #### 响应式规则
 

src/components/Exception/index.less

@@ -37,6 +37,7 @@
     .desc {
       color: @text-color-secondary;
       font-size: 20px;
+      line-height: 28px;
       margin-bottom: 16px;
     }