Proof of concept to IsPick util

[deusz]

Not sure of nested examples because it is not possible to achieve with Pick util.

Do you have idea how to implement it?

Follow up on: #15 (comment)

[deusz]

I think I have basic functionality of IsPick. For my purpose I still need sth more than IsPick, because I need to check also nested props and arrays.
But IsPick is a good start.

[garronej]

Thank you for your PR!
Everything looks good to me!
I just added some simple test case that helps grasp what this is about, whould you merge: #16

Would you go the extra mile of adding a documentation page for it? Here is the invite link.
It's realy easy to eddit. GitBook provide a "what you see is what you get" editor.

Thanks again.