Update cloudinary.md (#6489)

Typo in documentation which caused 'e is not iterable' while uploading images.

Co-authored-by: Martin Jagodic <jagodicmartin1@gmail.com>

Author: Griffin38

website/content/docs/cloudinary.md

@@ -102,11 +102,11 @@ fields: # The fields each document in this collection have
   media_library:
     config:
       default_transformations:
-        - fetch_format: auto
-          width: 300    
-          quality: auto
-          crop: fill
-          effect: grayscale
+        - - fetch_format: auto
+            width: 300    
+            quality: auto
+            crop: fill
+            effect: grayscale
 ```
 
 ## Inserting Cloudinary URL in page templates