update fftfreq and rfftfreq docstring

Author: vtavana

dpnp/dpnp_array.py

@@ -737,8 +737,9 @@ def copy(self, order="C", device=None, usm_type=None, sycl_queue=None):
 
         Notes
         -----
-        This function is the preferred method for creating an array copy. The
-        function :func:`dpnp.copy` is similar, but it defaults to using order 'K'.
+        This function is the preferred method for creating an array copy.
+        The function :func:`dpnp.copy` is similar, but it defaults to using
+        order ``"K"``.
 
         Examples
         --------

dpnp/dpnp_iface_arraycreation.py

@@ -787,7 +787,8 @@ def copy(
         includes scalars, lists, lists of tuples, tuples, tuples of tuples,
         tuples of lists, and ndarrays.
     order : {"C", "F", "A", "K"}, optional
-        Memory layout of the newly output array. Default: "K".
+        Memory layout of the newly output array.
+        Default: ``"K"``.
     device : {None, string, SyclDevice, SyclQueue}, optional
         An array API concept of device where the output array is created.
         The `device` can be ``None`` (the default), an OneAPI filter selector

dpnp/fft/dpnp_iface_fft.py

@@ -224,7 +224,10 @@ def fftfreq(n, d=1.0, device=None, usm_type=None, sycl_queue=None):
         The type of SYCL USM allocation for the output array.
         Default: ``None``.
     sycl_queue : {None, SyclQueue}, optional
-        A SYCL queue to use for output array allocation and copying.
+        A SYCL queue to use for output array allocation and copying. The
+        `sycl_queue` can be passed as ``None`` (the default), which means
+        to get the SYCL queue from `device` keyword if present or to use
+        a default queue.
         Default: ``None``.
 
     Returns
@@ -1148,7 +1151,10 @@ def rfftfreq(n, d=1.0, device=None, usm_type=None, sycl_queue=None):
         The type of SYCL USM allocation for the output array.
         Default: ``None``.
     sycl_queue : {None, SyclQueue}, optional
-        A SYCL queue to use for output array allocation and copying.
+        A SYCL queue to use for output array allocation and copying. The
+        `sycl_queue` can be passed as ``None`` (the default), which means
+        to get the SYCL queue from `device` keyword if present or to use
+        a default queue.
         Default: ``None``.
 
     Returns