Formatted the default value and cleaned some trailing spaces.

website/source/docs/builders/googlecompute.html.md

@@ -172,8 +172,13 @@ builder.
     to the region hosting the specified `zone`.
 
 -   `scopes` (array of strings) - The service account scopes for launched instance.
-    Defaults to
-    `["https://www.googleapis.com/auth/userinfo.email", "https://www.googleapis.com/auth/compute", "https://www.googleapis.com/auth/devstorage.full_control"]`.
+    Defaults to:
+
+``` {.json}
+[ "https://www.googleapis.com/auth/userinfo.email",
+  "https://www.googleapis.com/auth/compute",
+  "https://www.googleapis.com/auth/devstorage.full_control" ]
+```
 
 -   `source_image_project_id` (string) - The project ID of the
     project containing the source image.