detect error for iOS #60
Description
It would be nice to add a callback parameter to detect user cancellation (readerSessionInvalidationErrorUserCanceled) of the readerSession or any other error: https://developer.apple.com/documentation/corenfc/building_an_nfc_tag-reader_app#3240405
I'm new in iOS/swift, so i tried to understand the code, but had some problems with it :D