refactoring: changed description mistake for kilometers

src/convert_M_in_KM.c

@@ -1,6 +1,6 @@
 #include "convert_M_in_KM.h"
 
-// convert length for double metre into kilometre
+// convert length for double metre into kilometers
 double meter_to_kilometer(double meter) {
     return meter / 1000.0;
 }