pythongh-99908 Update class documentation to use a modernized example

Doc/tutorial/classes.rst

@@ -738,18 +738,22 @@ Odds and Ends
 =============
 
 Sometimes it is useful to have a data type similar to the Pascal "record" or C
-"struct", bundling together a few named data items.  An empty class definition
-will do nicely::
-
-   class Employee:
-       pass
-
-   john = Employee()  # Create an empty employee record
-
-   # Fill the fields of the record
-   john.name = 'John Doe'
-   john.dept = 'computer lab'
-   john.salary = 1000
+"struct", bundling together a few named data items. The idiomatic approach
+is to use :mod:`dataclasses` for this purpose::
+
+    from dataclasses import dataclasses
+
+    @dataclass
+    class Employee:
+        name: str
+        dept: str
+        salary: int
+
+    john = Employee("john", "computer lab", 1000)
+    >>> john.dept
+    # "computer lab"
+    >>> john.salary
+    # '1000'
 
 A piece of Python code that expects a particular abstract data type can often be
 passed a class that emulates the methods of that data type instead.  For