docs(ngInit): fix code block not being displayed in the note section

Closes angular#10791

Author: Boshen

src/ng/directive/ngInit.js

@@ -19,7 +19,7 @@
  * **Note**: If you have assignment in `ngInit` along with {@link ng.$filter `$filter`}, make
  * sure you have parenthesis for correct precedence:
  * <pre class="prettyprint">
- *   <div ng-init="test1 = (data | orderBy:'name')"></div>
+ * `<div ng-init="test1 = (data | orderBy:'name')"></div>`
  * </pre>
  * </div>
  *