message: fix(aio): Typo in Setup Anatomy documentation page
  Solves
diff: @@ -317,7 +317,7 @@ If you do, this page can help you understand their purpose.
  Optional extra SystemJS configuration.
  - A way to add SystemJS mappings, such as for appliation _barrels_,
  + A way to add SystemJS mappings, such as for application _barrels_,
  without changing the original `system.config.js`.
  </td>
  