Reorganizing library structure, prep for 2.0.0

drivers/AVR/DigitalIO/examples/DigitalPinBlink/DigitalPinBlink.ino

@@ -0,0 +1,12 @@
+#include <DigitalIO.h>
+// Create object for pin 13 in output mode and demo toggle().
+DigitalPin<13> pin13(OUTPUT);
+
+void setup() {}
+
+void loop() {
+  // toggle is a two byte instruction that executes
+  // in two cycles or 125 ns on a 16 MHz CPU
+  pin13.toggle();
+  delay(250);
+}