docs(ngInclude): add warning to onload function cause breaks in IE11

Closes angular#12493

Author: kutyel

src/ng/directive/ngInclude.js

@@ -35,6 +35,12 @@
  *                 make sure you wrap it in **single** quotes, e.g. `src="'myPartialTemplate.html'"`.
  * @param {string=} onload Expression to evaluate when a new partial is loaded.
  *
+ *                  <div class="alert alert-warning">
+ *                  **Note:** Seems like the onload attribute is being handled differently by different browsers,
+ *                  like with SVG elements in IE11. To fix this, you can instead use `data-onload`
+ *                  in ng-include and it will work, because directives normalize the attribute names.
+ *                  </div>
+ *
  * @param {string=} autoscroll Whether `ngInclude` should call {@link ng.$anchorScroll
  *                  $anchorScroll} to scroll the viewport after the content is loaded.
  *