Readme: api vs examples mismatch

[WORMSS]

Your Readme currently lists the api as

open(function, function, function, function)

but your example has

open(string, function, function, function, function)

I haven't used the package yet to know which is the correct api, I am just doing the Typescript boilerplate for it, but just noticed the inconsistency.

PS: expect a PR for typescript typings.

[Even Rognlien]

👍 I have updated the readme in the master branch.