Inaccurate docs for <ion-ripple-effect>

[mxdmedia]

URL
https://ionicframework.com/docs/api/ripple-effect

What is missing or inaccurate about the content on this page?
According to the docs, one can add the material ripple effect to any element, by adding the <ion-ripple-effect> component as a child to the element. However, this does not work properly in the latest release of Ionic 4. In order for the ripple to work properly, two more steps are necessary.

1. For the ripple to show up at all, the container element must have the ion-activatable class added to it.
2. To keep the ripple effect from overflowing the container, it should also have its css position property set to relative

For example, the <div> example in the docs should look like this:

<div class="ion-activatable" style="position: relative">
  <ion-ripple-effect></ion-ripple-effect>
  A plain div with a ripple effect
</div>