Does not offer option to build with rollup

[WickyNilliams]

The docs here imply that it should be possible to configure rollup for building through the generator, but I am not seeing any such option. https://open-wc.org/docs/building/rollup/

There is some scaffolding here, but it doesn't seem to be used https://github.com/open-wc/create/tree/master/src/generators/building-rollup-ts

Am I missing something?