import/no-extraneous-dependencies use the closest package.json + the root's one

[maksnester]

For the monorepo setup where shared deps are dropped into the root package.json it'd be handy to specify root package.json as an additional source to check for dependencies.

Right now I only have the option to specify packageDir but I don't see how I could use it to consider only the closest package.json + the root's one.

[ljharb]

Can you explain more about your practice of putting shared deps in the root?