docs: update identity map

identity-map/src/main/java/com/iluwatar/identitymap/IdNotFoundException.java

@@ -25,7 +25,7 @@
 package com.iluwatar.identitymap;
 
 /**
- * Using Runtime Exception to control the flow in case Person Id doesn not exist.
+ * Using Runtime Exception to control the flow in case Person Id doesn't exist.
  */
 public class IdNotFoundException extends RuntimeException {
   public IdNotFoundException(final String message) {

identity-map/src/main/java/com/iluwatar/identitymap/Person.java

@@ -24,6 +24,7 @@
  */
 package com.iluwatar.identitymap;
 
+import java.io.Serial;
 import java.io.Serializable;
 import lombok.AllArgsConstructor;
 import lombok.EqualsAndHashCode;
@@ -39,6 +40,7 @@ import lombok.Setter;
 @AllArgsConstructor
 public final class Person implements Serializable {
 
+  @Serial
   private static final long serialVersionUID = 1L;
 
   @EqualsAndHashCode.Include