[w3c/payment-request] .updateWith() example says "throws" (#620)

The `updateWith()` example says that `.updateWith()` throws... which is kinda wrong... it rejects the `responsePromise` instead, causing `.show()` to look like it threw when in an async function.  

That should be fixed or it will cause confusion. 

-- 
You are receiving this because you are subscribed to this thread.
Reply to this email directly or view it on GitHub:
https://github.com/w3c/payment-request/issues/620