chore(core): finish installation and theming

src/app/app.html

@@ -1,2 +1 @@
 <router-outlet/>
-<p-button label="Test"/>

src/app/app.ts

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