Optionator uses https://github.com/gkz/levn for the definition of the values of its options. This allows you to have complex types like objects and arrays as the input to your options.

`:` is a special token, used to separate keys from values when inputting objects.

I would recommend either having the type `[String]`, and using the shorted syntax of a prepended `+` to indicate that you can write. eg. `require,+exports`

Another slightly more verbose option would be to use the type `Object`, and have the input: `require:r,exports:rw` which would result in `{require: "r", exports: "rw"}`