Integrate ScrollService into multiple components.

frontend/src/app/about/about.component.ts

@@ -1,4 +1,5 @@
 import {Component} from '@angular/core';
+import {ScrollService} from '../scroll/scroll.service';
 
 @Component({
   selector: 'app-about',
@@ -7,5 +8,6 @@ import {Component} from '@angular/core';
   styleUrl: './about.component.scss'
 })
 export class AboutComponent {
-  scrollService: any;
+  constructor(public scrollService: ScrollService) {
+  }
 }