Add a link to the "Create content once and publish any & everywhere" feature on the About Drupal 9 page

Problem/Motivation

There is no link to the feature at the "Create content once and publish any & everywhere" feature About Drupal 9 page.

Steps to reproduce

1. Go to the https://www.drupal.org/about/9#benefits-drupals-continuous-innovation-de... .
2. Mouse hover over the "Create content once and publish any & everywhere" feature.

Proposed resolution

Put a link to the https://www.drupal.org/features/content-as-a-service at the "Create content once and publish any & everywhere" feature on the About Drupal 9 page.

Remaining tasks

The About Drupal 9 page content change.

User interface changes

The "Create content once and publish any & everywhere" text becomes a clickable link, the landing page exists already, https://www.drupal.org/features/content-as-a-service .

API changes

None.

Data model changes

None.