[Docs] Fix docstring format (#816)

* [Docs] Fix docstring format

* minor refine

* minor refine

mmengine/optim/optimizer/default_constructor.py

@@ -66,21 +66,22 @@ class DefaultOptimWrapperConstructor:
 
     Args:
         optim_wrapper_cfg (dict): The config dict of the optimizer wrapper.
-            Positional fields are
 
-                - ``type``: class name of the OptimizerWrapper
-                - ``optimizer``: The configuration of optimizer.
+            Required fields of ``optim_wrapper_cfg`` are
 
-            Optional fields are
+            - ``type``: class name of the OptimizerWrapper
+            - ``optimizer``: The configuration of optimizer.
 
-                - any arguments of the corresponding optimizer wrapper type,
-                  e.g., accumulative_counts, clip_grad, etc.
+            Optional fields of ``optim_wrapper_cfg`` are
 
-        The positional fields of ``optimizer`` are
+            - any arguments of the corresponding optimizer wrapper type,
+              e.g., accumulative_counts, clip_grad, etc.
+
+            Required fields of ``optimizer`` are
 
             - `type`: class name of the optimizer.
 
-        Optional fields are
+            Optional fields of ``optimizer`` are
 
             - any arguments of the corresponding optimizer type, e.g.,
               lr, weight_decay, momentum, etc.

mmengine/visualization/vis_backend.py

@@ -498,14 +498,13 @@ class TensorboardVisBackend(BaseVisBackend):
     Examples:
         >>> from mmengine.visualization import TensorboardVisBackend
         >>> import numpy as np
-        >>> tensorboard_vis_backend = \
-        >>>     TensorboardVisBackend(save_dir='temp_dir')
-        >>> img=np.random.randint(0, 256, size=(10, 10, 3))
-        >>> tensorboard_vis_backend.add_image('img', img)
-        >>> tensorboard_vis_backend.add_scaler('mAP', 0.6)
-        >>> tensorboard_vis_backend.add_scalars({'loss': 0.1,'acc':0.8})
+        >>> vis_backend = TensorboardVisBackend(save_dir='temp_dir')
+        >>> img = np.random.randint(0, 256, size=(10, 10, 3))
+        >>> vis_backend.add_image('img', img)
+        >>> vis_backend.add_scaler('mAP', 0.6)
+        >>> vis_backend.add_scalars({'loss': 0.1,'acc':0.8})
         >>> cfg = Config(dict(a=1, b=dict(b1=[0, 1])))
-        >>> tensorboard_vis_backend.add_config(cfg)
+        >>> vis_backend.add_config(cfg)
 
     Args:
         save_dir (str): The root directory to save the files