message: Fix overflow in navbar with visible score board link
diff: <i class="fas fa-trophy fa-lg"></i>
  {{"TITLE_SCORE_BOARD" | translate}}
  </a>
  - <a mat-button routerLink="/about">
  +
  + <a mat-button routerLink="/about" fxShow fxHide.lt-md>
  <i class="fas fa-info-circle fa-lg"></i>
  {{"TITLE_ABOUT" | translate}}
  </a>
  + <a mat-icon-button routerLink="/about" fxHide fxShow.lt-md>
  + <i class="fas fa-info-circle fa-lg"></i>
  + </a>
  - <a *ngIf="gitHubRibbon" mat-button href="/redirect?to=https://github.com/bkimminich/juice-shop">
  + <a *ngIf="gitHubRibbon" mat-button href="/redirect?to=https://github.com/bkimminich/juice-shop" fxShow fxHide.lt-md>
  <i class="fab fa-github fa-lg"></i> GitHub
  </a>
  + <a *ngIf="gitHubRibbon" mat-icon-button href="/redirect?to=https://github.com/bkimminich/juice-shop" fxHide fxShow.lt-md>
  + <i class="fab fa-github fa-lg"></i>
  + </a>
  </mat-toolbar-row>
  <mat-toolbar-row fxLayout="row" fxHide fxShow.lt-lg>
  