feature: allow users to include a package.json instead of just using `npm init -f`

[ORESoftware]

allow users to include a package.json instead of just using npm init -f

Users can add a package.json file:

.r2g/package.json

which will be the package.json file of Y, the testbed project.

In that package.json file, they can include test dependencies if they want.

This might not be a good idea, because it may conflate deps that won't actually exist IRL.

[ORESoftware]

this is almost certainly a bad idea