Provide an option to preserve the state of the node_modules when packaging about electron-packager

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[MarshallOfSound]

We have an algorithm that parses our dependency graph to decide which files are necessary at runtime so we can delete the rest. This results in a mismatch of the state of the "node_modules/" directory and the package.json. We don't want to simply put these packages in devDependencies because we still want to use the two fields to separate packages that are shipped vs. packages that ara only used for development. Allowing the electron-packager to skip the dependency check will save us from doing the package.json manipulation.

You can either do what you're asking and disable pruning prune: false in packager options. Or change your logic to be more Correct ™️ similar to what forge does which is ignore things via the packager ignore config instead of deleting things before packager gets a go at things.