refactor: use standalone component for demo (#231)

Reduces the amount of boilerplate by using a standalone component in the demo.

Author: crisbeto

src/demo/app/demo.component.ts

@@ -1,9 +1,14 @@
 import {Component} from '@angular/core';
+import {CommonModule} from '@angular/common';
+import {FormsModule} from '@angular/forms';
+import {RoundProgressModule} from 'angular-svg-round-progressbar';
 
 @Component({
   selector: 'demo',
   templateUrl: './demo.component.html',
   styleUrls: ['./demo.component.css'],
+  standalone: true,
+  imports: [RoundProgressModule, CommonModule, FormsModule]
 })
 export class DemoComponent {
   current = 27;

src/demo/app/demo.module.ts

@@ -1,13 +1,10 @@
 import {enableProdMode} from '@angular/core';
-import {platformBrowserDynamic} from '@angular/platform-browser-dynamic';
-
-import {DemoModule} from './app/demo.module';
+import {bootstrapApplication} from '@angular/platform-browser';
+import {DemoComponent} from './app/demo.component';
 import {environment} from './environments/environment';
 
 if (environment.production) {
   enableProdMode();
 }
 
-platformBrowserDynamic()
-  .bootstrapModule(DemoModule)
-  .catch(error => console.error(error));
+bootstrapApplication(DemoComponent).catch(error => console.error(error));