gh-99908: Tutorial: Modernize the 'data-record class' example (#100499)

Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>

Doc/tutorial/classes.rst

@@ -738,18 +738,24 @@ 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
+"struct", bundling together a few named data items. The idiomatic approach
-will do nicely::
+is to use :mod:`dataclasses` for this purpose::
 
+    from dataclasses import dataclasses
+
+    @dataclass
     class Employee:
-       pass
+        name: str
+        dept: str
+        salary: int
 
-   john = Employee()  # Create an empty employee record
+::
 
-   # Fill the fields of the record
+    >>> john = Employee('john', 'computer lab', 1000)
-   john.name = 'John Doe'
+    >>> john.dept
-   john.dept = 'computer lab'
+    'computer lab'
-   john.salary = 1000
+    >>> 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