Moved pprintable serial to arduino directory.

src/devices/arduino/printable_serial.cpp

@@ -0,0 +1,21 @@
+#include <sta/debug/printing/printable_serial.hpp>
+
+#ifdef STA_PLATFORM_ARDUINO
+
+#include <sta/devices/arduino/hal.hpp>
+
+namespace sta
+{
+    PrintableSerial::PrintableSerial(unsigned long baud)
+        : Printable{}
+    {
+        Serial.begin(baud);
+    }
+
+    void PrintableSerial::print(const char * str, size_t length)
+    {
+        Serial.write(str);
+    }
+} // namespace sta
+
+#endif // STA_PLATFORM_ARDUINO