message: docs: correct path reference in upgrade guide
  The incorrect path is referenced, this is confusing to users following the "Upgrading from AngularJS" guide.
  PR Close
diff: @@ -1279,7 +1279,7 @@ The arguments are the same as you would pass to `angular.bootstrap` if you were
  bootstrapping AngularJS: the root element of the application; and an array of the
  AngularJS 1.x modules that you want to load.
  -Finally, bootstrap the `AppModule` in `src/main.ts`.
  +Finally, bootstrap the `AppModule` in `app/main.ts`.
  This file has been configured as the application entrypoint in `systemjs.config.js`,
  so it is already being loaded by the browser.
  