refine bsd doc (#48882)

python/paddle/nn/decode.py

@@ -26,8 +26,6 @@ __all__ = []
 
 class Decoder:
     """
-        :api_attr: Static Graph
-
     Decoder is the base class for any decoder instance used in `dynamic_decode`.
     It provides interface for output generation for one time step, which can be
     used to generate sequences.
@@ -146,7 +144,8 @@ class BeamSearchDecoder(Decoder):
     Please refer to `Beam search <https://en.wikipedia.org/wiki/Beam_search>`_
     for more details.
 
-    **NOTE** When decoding with beam search, the `inputs` and `states` of cell
+    Note:
+        When decoding with beam search, the `inputs` and `states` of cell
         would be tiled to `beam_size` (unsqueeze and tile), resulting to shapes like
         `[batch_size * beam_size, ...]` , which is built into `BeamSearchDecoder` and
         done automatically. Thus any other tensor with shape `[batch_size, ...]` used