nested JSON
I have a couple of the MH-Z19 CO2 sensors connected to Tasmota'd ESP32 modules which send the measurements to MQTT like:

`SENSOR = {"Time":"2021-08-23T10:22:13","MHZ19B":{"Model":"B","CarbonDioxide":589,"Temperature":27.0},"ESP32":{"Temperature":34.4},"TempUnit":"C"}
`

Is it possible with the current build to extract the CarbonDioxide and Temperature Values from the inner MHZ19B structure ?

(I don't see any examples that appear to deal with this structure).
