doc: fix undocumented selectable prop of Menu

components/dropdown/index.en-US.md

@@ -27,7 +27,7 @@ You can get the menu list by `antd.Menu`, and set a callback function `onSelect`
 
 > Warning: You must set a unique `key` for `Menu.Item`.
 
-> Remove the highlighted style after click menu item via `<Menu selectedKeys={[]}>`.
+> Remove the highlighted style after click menu item via `<Menu selectable={false}>`.
 
 ### Dropdown.Button
 

components/dropdown/index.zh-CN.md

@@ -28,7 +28,7 @@ title: Dropdown
 
 > 注意： Menu.Item 必须设置唯一的 key 属性。
 
-> 如果希望去掉菜单选中的背景效果，可以指定 `<Menu selectedKeys={[]}>`.
+> 如果希望去掉菜单选中的背景效果，可以指定 `<Menu selectable={false}>`.
 
 ### Dropdown.Button
 

components/menu/index.en-US.md

@@ -43,6 +43,7 @@ More layouts with navigation: [layout](/components/layout).
 | inlineIndent | indent px of inline menu item on each level | number | 24 |
 | multiple | Allow select multiple item | boolean | false |
 | inlineCollapsed | specified the collapsed status when menu is inline mode | boolean | - |
+| selectable | Allow to be selected | boolean | true |
 
 > More options in [rc-menu](https://github.com/react-component/menu#api)
 

components/menu/index.zh-CN.md

@@ -43,6 +43,7 @@ subtitle: 导航菜单
 | inlineIndent | inline 模式的菜单缩进宽度 | number | 24 |
 | multiple | 是否允许多选 | boolean | false |
 | inlineCollapsed | inline 时菜单是否收起状态 | boolean | - |
+| selectable | 是否允许选中 | boolean | true |
 
 > More options in [rc-menu](https://github.com/react-component/menu#api)