adding SPDX to arduino code

and none since it is for Pico only and not an available platform

Author: BlitzCityDIY

…logger_Example/.feather_rp2040.test.only …owbell_Adalogger_Example/.none.test.onlyPiCowbell_Adalogger_Examples/Arduino_PiCowbell_Adalogger_Example/.feather_rp2040.test.only renamed to PiCowbell_Adalogger_Examples/Arduino_PiCowbell_Adalogger_Example/.none.test.only PiCowbell_Adalogger_Examples/Arduino_PiCowbell_Adalogger_Example/.feather_rp2040.test.only renamed to PiCowbell_Adalogger_Examples/Arduino_PiCowbell_Adalogger_Example/.none.test.only

@@ -1,3 +1,7 @@
+// SPDX-FileCopyrightText: 2023 Liz Clark for Adafruit Industries
+//
+// SPDX-License-Identifier: MIT
+
 const int _MISO = 16;
 const int _MOSI = 19;
 const int _CS = 17;