Update query-vision-models.mdx

Add snippets related to dependencies installation

Author: fpagny

pages/generative-apis/how-to/query-vision-models.mdx

@@ -123,7 +123,13 @@ A conversation style may include a default system prompt. You may set this promp
 1. **Image URLs**: If the image is available online, you can just include the image URL in your request as demonstrated above. This approach is simple and does not require any encoding.
 2. **Base64 encoded**: image Base64 encoding is a standard way to transform binary data, like images, into a text format, making it easier to transmit over the internet.
 
-The following Python code sample shows you how to encode an image in base64 format and pass it to your request payload.
+To encode Base64 images in Python, you first need to install `Pillow` library:
+
+```bash
+pip install pillow
+```
+
+Then, the following Python code sample shows you how to encode an image in base64 format and pass it to your request payload:
 
 ```python
 import base64
@@ -156,8 +162,7 @@ payload = {
                 }
             ]
         }
-    ],
-    ... # other parameters
+    ]
 }
 
 ```