Add detailed docstrings for NullablePositiveOrZeroInt class and its methods to enhance documentation and clarify functionality.

Author: n1nj4t4nuk1

pyvalueobjects/numbers/nullable_positive_or_zero_int.py

@@ -5,6 +5,13 @@
 
 
 class NullablePositiveOrZeroInt(_nullable_cls):
+    """
+    A nullable value object representing a positive integer or zero. Inherits from a nullable version of PositiveOrZeroInt and allows the value to be None.
+    """
 
     def __init__(self, value: int = None):
+        """
+        Initialize the NullablePositiveOrZeroInt object with the given positive integer or zero value or None.
+        :param value: A positive integer or zero value, or None.
+        """
         super().__init__(value)