DOC: fix SA01,ES01 for pandas.PeriodDtype.freq (#59796)

Author: tuhinsharma121

ci/code_checks.sh

@@ -72,7 +72,6 @@ if [[ -z "$CHECK" || "$CHECK" == "docstrings" ]]; then
         -i "pandas.Series.dt PR01" `# Accessors are implemented as classes, but we do not document the Parameters section` \
         -i "pandas.Period.freq GL08" \
         -i "pandas.Period.ordinal GL08" \
-        -i "pandas.PeriodDtype.freq SA01" \
         -i "pandas.RangeIndex.from_range PR01,SA01" \
         -i "pandas.RangeIndex.step SA01" \
         -i "pandas.Series.cat.add_categories PR01,PR02" \

pandas/core/dtypes/dtypes.py

@@ -1065,6 +1065,20 @@ def freq(self) -> BaseOffset:
         """
         The frequency object of this PeriodDtype.
 
+        The `freq` property returns the `BaseOffset` object that represents the
+        frequency of the PeriodDtype. This frequency specifies the interval (e.g.,
+        daily, monthly, yearly) associated with the Period type. It is essential
+        for operations that depend on time-based calculations within a period index
+        or series.
+
+        See Also
+        --------
+        Period : Represents a period of time.
+        PeriodIndex : Immutable ndarray holding ordinal values indicating
+            regular periods.
+        PeriodDtype : An ExtensionDtype for Period data.
+        date_range : Return a fixed frequency range of dates.
+
         Examples
         --------
         >>> dtype = pd.PeriodDtype(freq="D")