DOC: fix ES01 for pandas.CategoricalDtype (#60902)

* DOC: fix ES01 for  is a dtype representation for categorical data, which
    allows users to define a fixed set of values and optionally impose an ordering.
    This is particularly useful for handling categorical variables efficiently,
    as it can significantly reduce memory usage compared to using object dtypes.

* DOC: fix ES01 for pandas.CategoricalDtype

Author: tuhinsharma121

pandas/core/dtypes/dtypes.py

@@ -161,6 +161,11 @@ class CategoricalDtype(PandasExtensionDtype, ExtensionDtype):
     """
     Type for categorical data with the categories and orderedness.
 
+    It is a dtype representation for categorical data, which allows users to define
+    a fixed set of values and optionally impose an ordering. This is particularly
+    useful for handling categorical variables efficiently, as it can significantly
+    reduce memory usage compared to using object dtypes.
+
     Parameters
     ----------
     categories : sequence, optional