update index

Author: PatrickFarley

articles/ai-services/computer-vision/index.yml

@@ -69,12 +69,6 @@ conceptualContent:
         - itemType: concept
           text: Optical Character Recognition
           url: concept-ocr.md
-        - itemType: concept
-          text: Model customization
-          url: concept-model-customization.md
-        - itemType: concept
-          text: Background removal
-          url: concept-background-removal.md
         #- itemType: tutorial
         #  text: Generate metadata for images
         #  url: Tutorials/storage-lab-tutorial.md