Set all leaf pages to isLesson: true for multi-vector course

qdrant-landing/content/course/multi-vector-search/module-2/colpali-family.md

@@ -2,6 +2,7 @@
 title: "ColPali Family Overview"
 description: Explore the ColPali model family and their capabilities for multi-modal document understanding and retrieval.
 weight: 2
+isLesson: true
 ---
 
 {{< date >}} Module 2 {{< /date >}}

qdrant-landing/content/course/multi-vector-search/module-2/how-colpali-works.md

@@ -2,6 +2,7 @@
 title: "How ColPali Models Work"
 description: Understand the inner workings of ColPali models and how they generate multi-vector representations for images and documents.
 weight: 1
+isLesson: true
 ---
 
 {{< date >}} Module 2 {{< /date >}}

qdrant-landing/content/course/multi-vector-search/module-2/visual-interpretability.md

@@ -2,6 +2,7 @@
 title: "Visual Interpretability of ColPali"
 description: Learn how to visualize and interpret ColPali embeddings to understand what the model focuses on in images.
 weight: 3
+isLesson: true
 ---
 
 {{< date >}} Module 2 {{< /date >}}