DOC: fix ES01 for pandas.DataFrame.columns (#60836)

Author: tuhinsharma121

pandas/core/frame.py

@@ -13673,6 +13673,10 @@ def isin_(x):
         doc="""
         The column labels of the DataFrame.
 
+        This property holds the column names as a pandas ``Index`` object.
+        It provides an immutable sequence of column labels that can be
+        used for data selection, renaming, and alignment in DataFrame operations.
+
         Returns
         -------
         pandas.Index