message: docs: update to account for CLI changes
  This should help clarify the use of providedIn and correct the documentation where it was showing the use of a now depreciated CLI command flag.
  I am openly looking for feedback on this change to figure out the best wording.
  PR Close
diff: @@ -89,15 +89,8 @@ Registering the provider in the `@Injectable` metadata also allows Angular to op
  <div class="alert is-helpful">
  -If you need to, you can register providers at different levels:
  -in the `HeroesComponent`, in the `AppComponent`, in the `AppModule`.
  -For instance, you could have told the CLI to provide the service at the module level automatically by appending `--module=app`.
  -
  -<code-example language="sh" class="code-shell">
  - ng generate service hero --module=app
  -</code-example>
  -
  -To learn more about providers and injectors, see the [Dependency Injection guide](guide/dependency-injection).
  +To learn more about providers, see the [Providers section](guide/providers).
  +To learn more about injectors, see the [Dependency Injection guide](guide/dependency-injection).
  </div>
  