add interval for refreshing users (#12)

Reviewed-on: #12
Reviewed-by: Hernd Beidemann <huydw@proton.me>

src/app/employee-list/employee-list.component.ts

@@ -51,6 +51,10 @@ export class EmployeeListComponent implements OnInit{
 
   public ngOnInit(): void {
     this.employees$ = this.fetchEmployees();
+
+    setInterval(() => {
+      this.employees$ = this.fetchEmployees();
+    }, 5000)
   }
 
   private fetchEmployees(): Observable<Employee[]> {