dpo vlm blog post (#1844)

Co-authored-by: Quentin Gallouédec <quentin.gallouedec@huggingface.co>

docs/source/index.mdx

@@ -37,6 +37,10 @@ Check the appropriate sections of the documentation depending on your needs:
 
 <div class="mt-10">
   <div class="w-full flex flex-col space-y-4 md:space-y-0 md:grid md:grid-cols-2 md:gap-y-4 md:gap-x-5">
+    <a class="!no-underline border dark:border-gray-700 p-5 rounded-lg shadow hover:shadow-lg" href="https://huggingface.co/blog/dpo_vlm">
+      <img src="https://raw.githubusercontent.com/huggingface/blog/main/assets/dpo_vlm/thumbnail.png" alt="thumbnail">
+      <p class="text-gray-700">Preference Optimization for Vision Language Models with TRL</p>
+    </a>
     <a class="!no-underline border dark:border-gray-700 p-5 rounded-lg shadow hover:shadow-lg" href="https://huggingface.co/blog/rlhf">
       <img src="https://raw.githubusercontent.com/huggingface/blog/main/assets/120_rlhf/thumbnail.png" alt="thumbnail">
       <p class="text-gray-700">Illustrating Reinforcement Learning from Human Feedback</p>