Improve docs (#554)

* Update common.py

* Update inception_v1.py

Author: ProGamerGov

captum/optim/_utils/image/common.py

@@ -70,7 +70,7 @@ def make_grid_image(
 
 def show(
     x: torch.Tensor,
-    figsize: Optional[Tuple[int, int]] = (8, 8),
+    figsize: Optional[Tuple[int, int]] = None,
     scale: float = 255.0,
     images_per_row: Optional[int] = None,
     padding: int = 2,
@@ -84,7 +84,7 @@ def show(
         x (torch.Tensor): The tensor you want to display as an image.
         figsize (Tuple[int, int], optional): height & width to use
             for displaying the image figure.
-            Default: ``(8, 8)``
+            Default: ``None``
         scale (float, optional): Value to multiply the input tensor by so that
             it's value range is [0-255] for display.
             Default: ``255.0``

captum/optim/models/_image/inception_v1.py

@@ -53,7 +53,7 @@ def googlenet(
             Default: ``False``
 
     Returns:
-        **model** (InceptionV1): An Inception5h model instance.
+        model (InceptionV1): An Inception5h model instance.
     """
 
     if pretrained: