Update Python VLM example in README (#1178)

Existing example uses an undefined "read_image" function, and using
max_new_tokens in pipe.generate() resulted in an error with latest
nightly.

I updated the example to work out of the box. Makes it a bit longer, but
this section is hidden by default in the README, so it doesn't add to
visual clutter for people just visiting the repo. Also added links to
the relevant samples.

---------

Co-authored-by: Vladimir Zlobin <[email protected]>

README.md

@@ -117,17 +117,34 @@ optimum-cli export openvino --model openbmb/MiniCPM-V-2_6 --trust-remote-code --
 
 ### Run generation using VLMPipeline API in Python
 
+See [Visual Language Chat](https://github.com/openvinotoolkit/openvino.genai/tree/master/samples/python/visual_language_chat) for a demo application.
+
+Run the following command to download a sample image:
+
+```sh
+curl -O "https://storage.openvinotoolkit.org/test_data/images/dog.jpg"
+```
+
 ```python
+import numpy as np
+import openvino as ov
 import openvino_genai as ov_genai
-#Will run model on CPU, GPU is a possible option
+from PIL import Image
+
+# Choose GPU instead of CPU in the line below to run the model on Intel integrated or discrete GPU
 pipe = ov_genai.VLMPipeline("./MiniCPM-V-2_6/", "CPU")
-rgb = read_image("cat.jpg")
-print(pipe.generate(prompt, image=rgb, max_new_tokens=100))
+
+image = Image.open("dog.jpg")
+image_data = np.array(image.getdata()).reshape(1, image.size[1], image.size[0], 3).astype(np.uint8)
+image_data = ov.Tensor(image_data)  
+
+prompt = "Can you describe the image?"
+print(pipe.generate(prompt, image=image_data, max_new_tokens=100))
 ```
 
 ### Run generation using VLMPipeline in C++
 
-Code below requires installation of C++ compatible package (see [here](https://docs.openvino.ai/2024/get-started/install-openvino/install-openvino-genai.html#archive-installation) for more details)
+Code below requires installation of C++ compatible package (see [here](https://docs.openvino.ai/2024/get-started/install-openvino/install-openvino-genai.html#archive-installation) for more details). See [Visual Language Chat](https://github.com/openvinotoolkit/openvino.genai/tree/master/samples/cpp/visual_language_chat) for a demo application.
 
 ```cpp
 #include "load_image.hpp"