Fixed invalid html structure the ExpandableNavbarSectionComponent had an ul tag containing non-li tags

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

@@ -14,9 +14,9 @@
     </a>
     <ul @slide *ngIf="(active | async)" (click)="deactivateSection($event)"
         class="m-0 shadow-none border-top-0 dropdown-menu show">
-        <ng-container *ngFor="let subSection of (subSections$ | async)">
+        <li *ngFor="let subSection of (subSections$ | async)">
             <ng-container
                     *ngComponentOutlet="(sectionMap$ | async).get(subSection.id).component; injector: (sectionMap$ | async).get(subSection.id).injector;"></ng-container>
-        </ng-container>
+        </li>
     </ul>
 </div>