DOC: Fix some RT02 issues in docstrings (#50659)

* Corrected docstrings

* remove functions from code_checks.sh

ci/code_checks.sh

@@ -94,11 +94,6 @@ if [[ -z "$CHECK" || "$CHECK" == "docstrings" ]]; then
 	    pandas.Series.cat.remove_unused_categories \
 	    pandas.Index.all \
 	    pandas.Index.any \
-	    pandas.CategoricalIndex.rename_categories \
-	    pandas.CategoricalIndex.reorder_categories \
-	    pandas.CategoricalIndex.add_categories \
-	    pandas.CategoricalIndex.remove_categories \
-	    pandas.CategoricalIndex.remove_unused_categories \
 	    pandas.MultiIndex.drop \
 	    pandas.DatetimeIndex.to_pydatetime \
 	    pandas.TimedeltaIndex.to_pytimedelta \

pandas/core/arrays/categorical.py

@@ -935,7 +935,7 @@ def rename_categories(self, new_categories) -> Categorical:
 
         Returns
         -------
-        cat : Categorical
+        Categorical
             Categorical with renamed categories.
 
         Raises
@@ -1001,7 +1001,7 @@ def reorder_categories(self, new_categories, ordered=None):
 
         Returns
         -------
-        cat : Categorical
+        Categorical
             Categorical with reordered categories.
 
         Raises
@@ -1041,7 +1041,7 @@ def add_categories(self, new_categories) -> Categorical:
 
         Returns
         -------
-        cat : Categorical
+        Categorical
             Categorical with new categories added.
 
         Raises
@@ -1110,7 +1110,7 @@ def remove_categories(self, removals):
 
         Returns
         -------
-        cat : Categorical
+        Categorical
             Categorical with removed categories.
 
         Raises
@@ -1160,7 +1160,7 @@ def remove_unused_categories(self) -> Categorical:
 
         Returns
         -------
-        cat : Categorical
+        Categorical
             Categorical with unused categories dropped.
 
         See Also