styling(core): add star background

src/app/app.ts

@@ -1,10 +1,11 @@
 import { Component } from '@angular/core';
 import { RouterOutlet } from '@angular/router';
 import { ThemeSwitchService } from './core/service/theme-switch.service';
+import { Background } from "./core/components/background/background";
 
 @Component({
   selector: 'app-root',
-  imports: [RouterOutlet],
+  imports: [RouterOutlet, Background],
   templateUrl: './app.html',
 })
 export class App {