message: Always show description instead of name on smallest screens
diff: <mat-table *ngIf="challenges" [dataSource]="filterToDataSource(challenges)" [trackBy]="trackById">
  <ng-container matColumnDef="name">
  - <mat-header-cell *matHeaderCellDef translate>LABEL_NAME</mat-header-cell>
  - <mat-cell *matCellDef="let challenge"> {{challenge.name}}</mat-cell>
  + <mat-header-cell *matHeaderCellDef fxShow fxHide.lt-sm translate>LABEL_NAME</mat-header-cell>
  + <mat-cell *matCellDef="let challenge" fxShow fxHide.lt-sm> {{challenge.name}}</mat-cell>
  </ng-container>
  <ng-container matColumnDef="difficulty">
  </ng-container>
  <ng-container matColumnDef="description">
  - <mat-header-cell *matHeaderCellDef fxShow fxHide.lt-sm fxFlex="1 1 50%" translate>LABEL_DESCRIPTION
  + <mat-header-cell *matHeaderCellDef fxFlex="1 1 50%" translate>LABEL_DESCRIPTION
  </mat-header-cell>
  - <mat-cell *matCellDef="let challenge" fxShow fxHide.lt-sm fxFlex="1 1 50%">
  + <mat-cell *matCellDef="let challenge" fxFlex="1 1 50%">
  <div [innerHTML]="challenge.description"></div>
  </mat-cell>
  </ng-container>
  