Update Hello Skyward - scanf - updated legacy header (<Common.h>) to current (<miosix.h>), added header containing TRACE definition (Debug.h)

Hello-Skyward.md

@@ -101,7 +101,8 @@ This can be done through the _scanf()_ function:
  * THE SOFTWARE.
  */
 
-#include <Common.h>
+#include <miosix.h>
+#include <utils/Debug.h>
 
 using namespace miosix;