send_batch_data requires class instances when it should just require accept a list or dict

[evaherrada]

https://github.com/adafruit/Adafruit_CircuitPython_AdafruitIO/blob/main/adafruit_io/adafruit_io.py#L607

The _asdict method needs to be run on an instance of a class to get the class attributes. It would be easier for most users to just send a list or dict.

[evaherrada]

cc @brentru

[brentru]

@evaherrada Do you want to work on this issue next week? Tag me when there's a PR ready for review

[rbrian]

I’m available to help however I can, at the very least for testing.

[tyeth]

Closing this after merging #125 and releasing v5.9.0