fix(store): add missing StoreConfig and RootStoreConfig exports (#2009)

Closes #2007

Author: bhalash

modules/store/src/index.ts

@@ -47,5 +47,7 @@ export {
   StoreModule,
   StoreRootModule,
   StoreFeatureModule,
+  RootStoreConfig,
+  StoreConfig,
 } from './store_module';
 export { on, createReducer } from './reducer_creator';