#189, fix Options type definition and allow custom resolvers.

[RopoMen]

[philsturgeon]

I'll be happy to merge this if you can write a test showing it works as expected, and find somewhere to document how folks can use it. Make sure you rebase on main because there's been a few changes!

[RopoMen]

@philsturgeon I can rebase this, but I wont be writing any tests because this is just type definition update to make type checks pass.

I can try to find a place where I can place link to this https://apitools.dev/json-schema-ref-parser/docs/plugins/resolvers.html it tells how to use custom resolvers. Functionality is currently existing, but as I said, type checks wont pass.

I'll try to find some night when I can make rebase, I hope its in next weekend.