Searching how to install and set phpcs in a Drupal project I found the issue #2744463 that adds these tools into composer, but the documentation doesn't advise about that.
The issue notes the remaining tasks to update documentation such as https://www.drupal.org/node/1419988 and https://www.drupal.org/node/1587138 but I don't see it updated.
I found issue #2571965 too, which add a few new instructions.
I open this issue to remember to update the documentation if the new code style review workflow it's usable or the documentation it's deprecated.