feat: export Rsbuild types (#1314)

Author: Timeless0911

packages/core/src/index.ts

@@ -13,5 +13,6 @@ export { logger } from './utils/logger';
 
 export const version: string = RSLIB_VERSION;
 
+export type * as Rsbuild from '@rsbuild/core';
 export * as rsbuild from '@rsbuild/core';
-export { type Rspack, rspack } from '@rsbuild/core';
+export { type RsbuildPlugin, type Rspack, rspack } from '@rsbuild/core';