DOC: fix ES01 for pandas.DataFrame.set_flags and pandas.Series.set_flags (#60891)

Author: tuhinsharma121

pandas/core/generic.py

@@ -406,6 +406,12 @@ def set_flags(
         """
         Return a new object with updated flags.
 
+        This method creates a shallow copy of the original object, preserving its
+        underlying data while modifying its global flags. In particular, it allows
+        you to update properties such as whether duplicate labels are permitted. This
+        behavior is especially useful in method chains, where one wishes to
+        adjust DataFrame or Series characteristics without altering the original object.
+
         Parameters
         ----------
         copy : bool, default False