message: docs(aio): remove trailing underscore from provide_
  _provide_ was already emphasized in the previous paragraph
  PR Close
diff: @@ -80,7 +80,7 @@ You must _provide_ the `HeroService` in the _dependency injection system_
  before Angular can _inject_ it into the `HeroesComponent`,
  as you will do [below](#inject).
  -There are several ways to provide_ the `HeroService`:
  +There are several ways to provide the `HeroService`:
  in the `HeroesComponent`, in the `AppComponent`, in the `AppModule`.
  Each option has pros and cons.
  