message: docs: attributes for 'label' and 'input' elements were mixed up
  A label should be 'for' an input, and an 'input' should have an 'id'.
  PR Close
diff: <!-- #docregion add -->
  <div>
  - <label id="new-hero">Hero name: </label>
  - <input for="new-hero" #heroName />
  + <label for="new-hero">Hero name: </label>
  + <input id="new-hero" #heroName />
  <!-- (click) passes input value to add() and then clears the input -->
  <button class="add-button" (click)="add(heroName.value); heroName.value=''">
  