Create init package #234
Description
Create a separate init package which can be used to scaffold an empty directory.
Users could run it via a command like:
npx advent-of-code-runner/init
The packages / code required by init are only used by the init command, likewise after a directory is initialized there is no longer any need for the init code / packages. Breaking into two packages would bring the install sizes of both packages down. It would make running the npx init command much quicker because there is less to download and setup.
The downside is that now there is two packages to maintain, and they must be kept in sync. Less advanced users might also be confused by the two packages, however much of the usage is hidden behind npx and npm scripts.