Update Pillar and Card docs to use minimal example for image usage

Author: danielguillan

apps/docs/content/components/Card/react.mdx

@@ -131,7 +131,6 @@ Use the `Image` component to add an image to the `Card`. The `Image` component i
   <Card.Image
     src="https://via.placeholder.com/600x400/d3d9df/d3d9df.png"
     alt="placeholder, blank area with an gray background color"
-    aspectRatio="16:9"
   />
   <Card.Heading>Code search & code view</Card.Heading>
   <Card.Description>

apps/docs/content/components/Pillar/react.mdx

@@ -58,7 +58,6 @@ You can add an `image` to enhance the visual context.
   <Pillar.Image
     src="https://via.placeholder.com/600x400/d3d9df/d3d9df.png"
     alt="placeholder, blank area with an gray background color"
-    aspectRatio="16:9"
   />
   <Pillar.Heading>Code search & code view</Pillar.Heading>
   <Pillar.Description>