Multiple checkbox input.
type CheckboxesField<T extends NonNullableFieldValue = NonNullableFieldValue> = NonNullable<LabeledValue<T>>[];
string | number.type Features = CheckboxesField<"wifi" | "parking" | "pool">;
// Result: {
// value: "wifi" | "parking" | "pool",
// label: string,
// key: "wifi" | "parking" | "pool"
// }[] | []