fix(core): fix placement type for idea (#224)

Author: al-march

packages/core/src/lib/type.ts

@@ -1,5 +1,7 @@
 import { Middleware } from '@floating-ui/dom';
+import { AlignedPlacement, Side } from '@floating-ui/utils';
 
 export * from '@floating-ui/dom';
 
+export type Placement = Side | AlignedPlacement
 export type MiddlewareList = Array<Middleware | null | undefined | false>;