added convert cm into dm

src/convert_cm_in_dm.c

@@ -0,0 +1,7 @@
+
+#include "convert_cm_in_dm.h"
+#include <stdio.h>
+
+double cm_to_dm(double cm) {
+    return cm / 10.0;
+}

src/convert_cm_in_dm.h

@@ -0,0 +1,7 @@
+
+#ifndef THEADMIRALS_CONVERT_CM_TO_DM_H
+#define THEADMIRALS_CONVERT_CM_TO_DM_H
+
+double cm_to_dm(double cm);
+
+#endif //THEADMIRALS_CONVERT_CM_TO_DM_H