add content variable

src/app/header/content/content.component.html

-<p>content works!</p>
+<div id="content" *ngIf="content">
+  {{content}}
+</div>

src/app/header/content/content.component.ts

@@ -6,7 +6,7 @@ import { Component, OnInit } from '@angular/core';
   styleUrls: ['./content.component.scss']
 })
 export class ContentComponent implements OnInit {
-
+  content = null;
   constructor() { }
 
   ngOnInit(): void {