docs(ngAnimate): fix typo

Closes #12521

src/ngAnimate/module.js

@@ -53,7 +53,7 @@
  * CSS-based animations with ngAnimate are unique since they require no JavaScript code at all. By using a CSS class that we reference between our HTML
  * and CSS code we can create an animation that will be picked up by Angular when an the underlying directive performs an operation.
  *
- * The example below shows how an `enter` animation can be made possible on a element using `ng-if`:
+ * The example below shows how an `enter` animation can be made possible on an element using `ng-if`:
  *
  * ```html
  * <div ng-if="bool" class="fade">