Document the way to generate the CBOR encoding

Author: ilcato

src/ArduinoIoTCloud.cpp

@@ -346,6 +346,7 @@ void ArduinoIoTCloudClass::requestLastValue()
 {
   // Send the getLastValues CBOR message to the cloud
   // [{0: "r:m", 3: "getLastValues"}] = 81 A2 00 63 72 3A 6D 03 6D 67 65 74 4C 61 73 74 56 61 6C 75 65 73
+  // Use http://cbor.me to easily generate CBOR encoding
   const uint8_t CBOR_REQUEST_LAST_VALUE_MSG[] =  { 0x81, 0xA2, 0x00, 0x63, 0x72, 0x3A, 0x6D, 0x03, 0x6D, 0x67, 0x65, 0x74, 0x4C, 0x61, 0x73, 0x74, 0x56, 0x61, 0x6C, 0x75, 0x65, 0x73 };
   writeShadowOut(CBOR_REQUEST_LAST_VALUE_MSG, sizeof(CBOR_REQUEST_LAST_VALUE_MSG));
 }