message: docs(upgrade): remove outdated/non-applicable AOT section from upgrade guide
  The AOT compilation section of the `ngUpgrade` guide was
  outdated/non-applicable. This commit hides the section to avoid confusion.
  Fixing the section and re-introducing it is being tracked in
  PR Close
diff: @@ -960,6 +960,12 @@ angular.module('myHybridApp', [...])
  Once you introduce the Angular Router, using the Angular Router triggers navigations through the unified location service, still providing a single source for navigating with AngularJS and Angular.
  +<!--
  +TODO:
  +Correctly document how to use AOT with SystemJS-based `ngUpgrade` apps (or better yet update the
  +`ngUpgrade` examples/guides to use `@angular/cli`).
  +See https://github.com/angular/angular/issues/35989.
  +
  ## Using Ahead-of-time compilation with hybrid apps
  You can take advantage of Ahead-of-time (AOT) compilation on hybrid apps just like on any other
  @@ -979,6 +985,7 @@ bootstrap the hybrid app:
  </code-example>
  And that's all you need do to get the full benefit of AOT for Angular apps!
  +-->
  ## PhoneCat Upgrade Tutorial
  