(doc/fluxion/pixelshuffle) add/convert docstrings to mkdocstrings format

src/refiners/fluxion/layers/pixelshuffle.py

@@ -4,5 +4,16 @@ from refiners.fluxion.layers.module import Module
 
 
 class PixelUnshuffle(_PixelUnshuffle, Module):
+    """Pixel Unshuffle layer.
+
+    This layer wraps [`torch.nn.PixelUnshuffle`][torch.nn.PixelUnshuffle].
+
+    Receives:
+        (Float[Tensor, "batch in_channels in_height in_width"]):
+
+    Returns:
+        (Float[Tensor, "batch out_channels out_height out_width"]):
+    """
+
     def __init__(self, downscale_factor: int):
         _PixelUnshuffle.__init__(self, downscale_factor=downscale_factor)