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

src/refiners/fluxion/layers/padding.py

@@ -1,8 +1,19 @@
-from torch import nn
+from torch.nn import ReflectionPad2d as _ReflectionPad2d
 
 from refiners.fluxion.layers.module import Module
 
 
-class ReflectionPad2d(nn.ReflectionPad2d, Module):
+class ReflectionPad2d(_ReflectionPad2d, Module):
+    """Reflection padding layer.
+
+    This layer wraps [`torch.nn.ReflectionPad2d`][torch.nn.ReflectionPad2d].
+
+    Receives:
+        (Float[Tensor, "batch channels in_height in_width"]):
+
+    Returns:
+        (Float[Tensor, "batch channels out_height out_width"]):
+    """
+
     def __init__(self, padding: int) -> None:
         super().__init__(padding=padding)