refactoring: description added

src/arithmeticSubtraction.c

@@ -2,7 +2,7 @@
 #include "arithmeticSubtraction.h"
 
 #include <stdlib.h>
-//arithmetic Subtraction specification integer
+//arithmetic Subtraction specification integer 1 function
 int* subtraction_integer(int a, int b) {
     int* result= malloc(sizeof (int));
     *result=a - b;