message: Update platform.md
  The `MyPage` class is not prefixed with the `class` keyword.
diff: @@ -17,7 +17,7 @@ The Platform service can be used to get information about your current device. Y
  import { Platform } from '@ionic/angular';
  @Component({...})
  -export MyPage {
  +export class MyPage {
  constructor(public plt: Platform) {
  }
  