Azure IoT SDK example - RP2040 iothub_ll_c2d sample

1. Prepare IoT Hub and Device for this example 1.1. Azure portal [MUST] Same as 1.1. Azure portal in _1_APP_TELEMETRY_manual.md 1.2. Developer PC 1.2.1. SDK setting In the following pico-azure-iot-sdk-c/application/main.c source file, find the line similar to this and replace it as you want: (...) // The application you wish to use should be uncommented // //#define APP_TELEMETRY #define APP_C2D..