note for future ts support

[ORESoftware]

It would neat if dashdash could have TS support - I don't see @types/dashdash just yet.

https://stackoverflow.com/a/51334721/7898461

ATM, I am trying to create/derive an interface from the options array, that interface will define what the parsed options object looks like.

[karfau]

PR with related discussion: #37