fix: renamed train files

src/main/java/oving7/train/PassengerCar.java

@@ -7,7 +7,7 @@ package oving7.train;
  * @see TrainCar
  * @see CargoCar
  */
-public class PassengerCarDocs extends TrainCarDocs {
+public class PassengerCar extends TrainCar {
 
     // TODO: Add fields here
 
@@ -20,7 +20,7 @@ public class PassengerCarDocs extends TrainCarDocs {
      * 
      * @see PassengerCarTest#testWeight()
      */
-    public PassengerCarDocs(int deadWeight, int passengerCount) {
+    public PassengerCar(int deadWeight, int passengerCount) {
         // TODO: Implement this constructor
         super(deadWeight);
     }