`shouldRetryOnError` function usage not updated in "API" and "Error Handling"

[taesungh]

Following from vercel/swr#1574 and vercel/swr#1816, the shouldRetryOnError option can accept a function to conditionally determine if SWR should retry. The notes for Release 1.2.1 provide a basic usage example copied here.

useSWR(key, fetcher, {
  shouldRetryOnError: (error) => {
    // We skip retrying if the API is returning 404:
    if (error.status === 404) return false
    return true
  }
})

As such, it would be very helpful if the Error Retry section of Error Handling and the Options section of API could be updated with this new usage.

[piotr-cz]

Yeah, without docs update it's an undocumented feature