docs: add align #6885

Author: tangjinzhou

components/dropdown/index.en-US.md

@@ -16,8 +16,9 @@ When there are more than a few options to choose from, you can wrap them in a `D
 
 ### Dropdown
 
-| Property | Description | Type | Default |  |
+| Property | Description | Type | Default | Version |
 | --- | --- | --- | --- | --- |
+| align | this value will be merged into placement's config, please refer to the settings [dom-align](https://github.com/yiminghe/dom-align) | Object | - |  |
 | arrow | Whether the dropdown arrow should be open | boolean \| { pointAtCenter: boolean } | false | 3.3.0 |
 | destroyPopupOnHide | Whether destroy dropdown when hidden | boolean | false |  |
 | disabled | whether the dropdown menu is disabled | boolean | - |  |

components/dropdown/index.zh-CN.md

@@ -22,6 +22,7 @@ coverDark: https://mdn.alipayobjects.com/huamei_7uahnr/afts/img/A*5qm4S4Zgh2QAAA
 
 | 参数 | 说明 | 类型 | 默认值 |  |
 | --- | --- | --- | --- | --- |
+| align | 该值将合并到 placement 的配置中，设置参考 [dom-align](https://github.com/yiminghe/dom-align) | Object | 无 |  |
 | arrow | 下拉框箭头是否显示 | boolean \| { pointAtCenter: boolean } | false | 3.3.0 |
 | destroyPopupOnHide | 关闭后是否销毁 Dropdown | boolean | false | 3.0 |
 | disabled | 菜单是否禁用 | boolean | - |  |