CascaderPanel: export type (ElemeFE#21070)

Author: qige2016

types/element-ui.d.ts

@@ -82,6 +82,7 @@ import { ElDrawer } from './drawer'
 import { ElPopconfirm } from './popconfirm'
 import { ElSkeleton } from './skeleton'
 import { ElSkeletonItem } from './skeleton-item'
+import { ElCascaderPanel } from './cascader-panel'
 import { ElEmpty } from './empty'
 
 export interface InstallationOptions {
@@ -354,5 +355,8 @@ export class Skeleton extends ElSkeleton {}
 /** Skeleton Item Component */
 export class SkeletonItem extends ElSkeletonItem {}
 
+/** CascaderPanel Component */
+export class CascaderPanel extends ElCascaderPanel {}
+
 /** Empty Component */
 export class Empty extends ElEmpty {}