feat: deprecated dropdown center placement

Author: tangjinzhou

components/breadcrumb/BreadcrumbItem.tsx

@@ -30,7 +30,7 @@ export default defineComponent({
       const overlay = getPropsSlot(slots, props, 'overlay');
       if (overlay) {
         return (
-          <DropDown overlay={overlay} placement="bottomCenter">
+          <DropDown overlay={overlay} placement="bottom">
             <span class={`${prefixCls}-overlay-link`}>
               {breadcrumbItem}
               <DownOutlined />

components/dropdown/index.en-US.md

@@ -23,7 +23,7 @@ When there are more than a few options to choose from, you can wrap them in a `D
 | overlay(v-slot) | the dropdown menu | [Menu](/components/menu) | - |  |
 | overlayClassName | Class name of the dropdown root element | string | - |  |
 | overlayStyle | Style of the dropdown root element | object | - |  |
-| placement | placement of pop menu: `bottomLeft` `bottomCenter` `bottomRight` `topLeft` `topCenter` `topRight` | String | `bottomLeft` |  |
+| placement | placement of pop menu: `bottomLeft` `bottom` `bottomRight` `topLeft` `top` `topRight` | String | `bottomLeft` |  |
 | trigger | the trigger mode which executes the drop-down action, hover doesn't work on mobile device | Array<`click`\|`hover`\|`contextmenu`> | `['hover']` |  |
 | visible(v-model) | whether the dropdown menu is visible | boolean | - |  |
 
@@ -47,7 +47,7 @@ You should use [Menu](/components/menu/) as `overlay`. The menu items and divide
 | icon | Icon (appears on the right) | vNode \| slot | - | 1.5.0 |
 | loading | Set the loading status of button | boolean \| { delay: number } | false | 3.0 |
 | overlay(v-slot) | the dropdown menu | [Menu](/components/menu) | - |  |
-| placement | placement of pop menu: `bottomLeft` `bottomCenter` `bottomRight` `topLeft` `topCenter` `topRight` | String | `bottomLeft` |  |
+| placement | placement of pop menu: `bottomLeft` `bottom` `bottomRight` `topLeft` `top` `topRight` | String | `bottomLeft` |  |
 | size | size of the button, the same as [Button](/components/button) | string | `default` |  |
 | trigger | the trigger mode which executes the drop-down action | Array<`click`\|`hover`\|`contextmenu`> | `['hover']` |  |
 | type | type of the button, the same as [Button](/components/button) | string | `default` |  |

components/dropdown/index.zh-CN.md

@@ -27,7 +27,7 @@ cover: https://gw.alipayobjects.com/zos/alicdn/eedWN59yJ/Dropdown.svg
 | overlay(v-slot) | 菜单 | [Menu](/components/menu-cn) | - |  |
 | overlayClassName | 下拉根元素的类名称 | string | - |  |
 | overlayStyle | 下拉根元素的样式 | object | - |  |
-| placement | 菜单弹出位置：`bottomLeft` `bottomCenter` `bottomRight` `topLeft` `topCenter` `topRight` | String | `bottomLeft` |  |
+| placement | 菜单弹出位置：`bottomLeft` `bottom` `bottomRight` `topLeft` `top` `topRight` | String | `bottomLeft` |  |
 | trigger | 触发下拉的行为, 移动端不支持 hover | Array<`click`\|`hover`\|`contextmenu`> | `['hover']` |  |
 | visible(v-model) | 菜单是否显示 | boolean | - |  |
 
@@ -51,7 +51,7 @@ cover: https://gw.alipayobjects.com/zos/alicdn/eedWN59yJ/Dropdown.svg
 | icon | 右侧的 icon | VNode \| slot | - | 1.5.0 |
 | loading | 设置按钮载入状态 | boolean \| { delay: number } | false | 3.0 |
 | overlay(v-slot) | 菜单 | [Menu](/components/menu-cn/) | - |  |
-| placement | 菜单弹出位置：`bottomLeft` `bottomCenter` `bottomRight` `topLeft` `topCenter` `topRight` | String | `bottomLeft` |  |
+| placement | 菜单弹出位置：`bottomLeft` `bottom` `bottomRight` `topLeft` `top` `topRight` | String | `bottomLeft` |  |
 | size | 按钮大小，和 [Button](/components/button-cn/) 一致 | string | 'default' |  |
 | trigger | 触发下拉的行为 | Array<`click`\|`hover`\|`contextmenu`> | `['hover']` |  |
 | type | 按钮类型，和 [Button](/components/button-cn/) 一致 | string | 'default' |  |