Add 'Serial.begin()' to examples

examples/CopyFromSD/CopyFromSD.ino

   //pinMode(4, INPUT_PULLUP);
   //pinMode(10, INPUT_PULLUP);
 
+  Serial.begin(9600);
+
   // wait up to 10 seconds for Arduino Serial Monitor
   unsigned long startMillis = millis();
   while (!Serial && (millis() - startMillis < 10000)) ;

examples/EraseEverything/EraseEverything.ino

   //pinMode(4, INPUT_PULLUP);
   //pinMode(10, INPUT_PULLUP);
 
+  Serial.begin(9600);
+
   // wait up to 10 seconds for Arduino Serial Monitor
   unsigned long startMillis = millis();
   while (!Serial && (millis() - startMillis < 10000)) ;

examples/ListFiles/ListFiles.ino

   //pinMode(4, INPUT_PULLUP);
   //pinMode(10, INPUT_PULLUP);
 
+  Serial.begin(9600);
+
   // wait for Arduino Serial Monitor
   while (!Serial) ;
   delay(100);

examples/MP3Player/MP3Player.ino

 #define FLASH_CHIP_SELECT  6
 
 void setup() {
+  Serial.begin(9600);
   AudioMemory(8); //4
   delay(2000);
 

examples/RawHardwareTest/RawHardwareTest.ino

   //pinMode(4, INPUT_PULLUP);
   //pinMode(10, INPUT_PULLUP);
 
+  Serial.begin(9600);
+
   while (!Serial) ;
   delay(100);