message: docs(aio): fix typo in Attribute Directives documentation
  changed "appHightlight" to "appHighlight"
  PR Close
diff: <!-- #docregion -->
  <h1>My First Attribute Directive</h1>
  <!-- #docregion applied -->
  -<p appHightlight>Highlight me!</p>
  +<p appHighlight>Highlight me!</p>
  <!-- #enddocregion applied, -->
  <!-- #docregion color-1 -->
  -<p appHightlight highlightColor="yellow">Highlighted in yellow</p>
  -<p appHightlight [highlightColor]="'orange'">Highlighted in orange</p>
  +<p appHighlight highlightColor="yellow">Highlighted in yellow</p>
  +<p appHighlight [highlightColor]="'orange'">Highlighted in orange</p>
  <!-- #enddocregion color-1 -->
  <!-- #docregion color-2 -->
  -<p appHightlight [highlightColor]="color">Highlighted with parent component's color</p>
  +<p appHighlight [highlightColor]="color">Highlighted with parent component's color</p>
  <!-- #enddocregion color-2 -->
  