I don't know about a USB BUT this is what the Insignia dock kit includes a USB-C AC adapter for power outlet charging.
My experience with Insignia chargers and cables has been great with no issues ever.
I just bought some more Insignia iPhone/iPad charge cables, plugs and battery chargers, which were all high quality and actually better thickness of wires than Apple.
The Insignia dock is a bit shorter but it plug into the dock and into the plug wire with no issues.
I think this one is a steal when compared to Nintendo's $90 dock.