Update markdown

Author: MikeRayMSFT

docs/big-data-cluster/machine-learning-services.md

@@ -118,7 +118,7 @@ The following image demonstrates this process.
 :::image type="content" source="media/machine-learning-services/example-kube-enable-scripts.png" alt-text="demonstrate-configure-external-script-availability-group":::
 -->
 
-[![demonstrate-configure-external-script-availability-group](media/machine-learning-services/example-kube-enable-scripts.png)](/machine-learning-services/example-kube-enable-scripts.png#lightbox)
+[![](media/machine-learning-services/example-kube-enable-scripts.png "Demonstrate enable feature on Kubernetes")](/machine-learning-services/example-kube-enable-scripts.png#lightbox)
 
 You are now ready to run Python and R scripts on the master instance of Big Data Clusters. See the quickstarts under [Next steps](#next-steps) to run your first script.