Allow enter key to expand or contract menu based on current active status

src/app/navbar/expandable-navbar-section/expandable-navbar-section.component.html

@@ -1,5 +1,6 @@
+<ng-container *ngVar="(active | async) as isActive">
     <div class="nav-item dropdown expandable-navbar-section"
-    (keyup.enter)="activateSection($event)"
+        (keyup.enter)="isActive ? deactivateSection($event) : activateSection($event)"
         (mouseenter)="activateSection($event)"
         (mouseleave)="deactivateSection($event)">
         <a href="#" class="nav-link dropdown-toggle" routerLinkActive="active"
@@ -16,3 +17,4 @@
             </ng-container>
         </ul>
     </div>
+</ng-container>