You already have RouterModule.forRoot([]) imported in the app module, I am assuming you want to move to a separate file, if so, you need to create a file in the same folder as the app module with the name app-routing.module.ts and add the following code
import { RouterModule, Routes } from '@angular/router';
import { ListadoEmpleadosComponent } from './empleados/listado-empleados/listado-empleados.component';
import { NgModule } from '@angular/core';
export const routes: Routes = [
{ path: 'empleados', component: ListadoEmpleadosComponent },
{ path: '', redirectTo: 'empleados', pathMatch: 'full' },
{ path: '**', redirectTo: 'empleados', pathMatch: 'full' },
];
@NgModule({
imports: [RouterModule.forRoot(routes)],
exports: [RouterModule],
})
export class AppRoutingModule {}
P.S. if you generate an angular app using the angular CLI you will get a prompt to create app routing module which will create the file automatically.