What problem does this feature solve?

We generally recommend to use code-splitting route components when writing apps with vue-router, but the code generated by vue-cli when selecting the router feature does use static imports.

In order to make users adopt per-route code-splitting, we should demonstrate the necessary code in the generated router.js file

What does the proposed API look like?

Rewriting static imports in this file as dynamic imports.

I'll do a PR