minimist package: defaults key not exists

Hi, in the example:
https://github.com/oncletom/nodebook/blob/524edca4a97d937f23bb59db16a4d3ae21fa9cb8/chapter-08/examples/options/defaults.js#L4

The correct key is "default" (see the doc: https://www.npmjs.com/package/minimist/v/1.2.5).

Thank you for your work ! :)