Design Artifact: Funnel users from Auto DevOps setting to cluster creation

Right now, we inform the user that a domain name and cluster is necessary for Auto DevOps to work correctly via the following UI:

When first looking at this, I had no idea what this meant.

Proposal

Provide some context around what a cluster is for and why it is needed. You need a cluster for Auto DevOps to give it some place to run your application. Without it, Auto DevOps will be limited to building and testing your app.

Determine how to funnel users from the Auto DevOps settings to cluster creation.

This is directly related to https://gitlab.com/gitlab-org/gitlab-ce/issues/43466.