feat(injectionToken): create new challenge on injectionToken

apps/angular/injection-token/src/app/timer.component.ts

@@ -0,0 +1,13 @@
+import { Component } from '@angular/core';
+import { toSignal } from '@angular/core/rxjs-interop';
+import { interval } from 'rxjs';
+import { DEFAULT_TIMER } from './data';
+
+@Component({
+  selector: 'timer',
+  standalone: true,
+  template: ` Timer running {{ timer() }} `,
+})
+export class TimerComponent {
+  timer = toSignal(interval(DEFAULT_TIMER));
+}