DOC: Fixed PeriodArray api ref (#25526)

Author: TomAugspurger

doc/source/reference/arrays.rst

@@ -259,7 +259,7 @@ Every period in a ``PeriodArray`` must have the same ``freq``.
 .. autosummary::
    :toctree: api/
 
-   arrays.DatetimeArray
+   arrays.PeriodArray
    PeriodDtype
 
 .. _api.arrays.interval:

pandas/core/arrays/period.py

@@ -105,13 +105,16 @@ class PeriodArray(dtl.DatetimeLikeArrayMixin, dtl.DatelikeOps):
         is an ndarray of integers, when `freq` is required. When `values`
         is a PeriodArray (or box around), it's checked that ``values.freq``
         matches `freq`.
+    dtype : PeriodDtype, optional
+        A PeriodDtype instance from which to extract a `freq`. If both
+        `freq` and `dtype` are specified, then the frequencies must match.
     copy : bool, default False
         Whether to copy the ordinals before storing.
 
     See Also
     --------
     period_array : Create a new PeriodArray.
-    pandas.PeriodIndex : Immutable Index for period data.
+    PeriodIndex : Immutable Index for period data.
 
     Notes
     -----