What problem does this feature solve?

As a new cli user, a first impression after creating a new project with vue cli is the missing webpack config. A glance at the docs can clear this up, but I'd advocate for creating a default vue.config (or webpack file?) with a comment explaining why a webpack config file isn't there, what a vue.config file is, etc.

What does the proposed API look like?

Something like commented out examples of the general settings seen in the Vue UI, link to dos about extending vue config, etc.