Error in IR example for CPX

In the learning guide for the Circuit Playground Express, IR CPX to CPX example, the code has the following:

```
encoder = adafruit_irremote.GenericTransmit(header=[9500, 4500], one=[550, 550], zero=[550, 1700], trail=0)
```

However, the sample code from `adafruilt_irremote.py` has the following:

```
encoder = adafruit_irremote.GenericTransmit(header=[9000, 4500], one=[560, 1700], zero=[560, 560], trail=560)
```

The CPX example results in the receive data being the 1s compliment of the send data.

Start with the Circuit Playground Express learning guide's IR CPX-to-CPX example and compare its GenericTransmit settings with the sample in adafruit_irremote.py. Correct the example's encoder values, then verify that received data matches the sent data rather than being its one's complement.

Written by the indexing model from the issue text.