Added tooltip components

src/app/components/challenge-card/challenge-card.component.ts

@@ -0,0 +1,14 @@
+import { Component, OnInit } from '@angular/core';
+
+@Component({
+  selector: 'app-challenge-card',
+  templateUrl: './challenge-card.component.html',
+  styleUrls: ['./challenge-card.component.scss'],
+})
+export class ChallengeCardComponent  implements OnInit {
+
+  constructor() { }
+
+  ngOnInit() {}
+
+}