Update README.md

Author: martygubar

apex/README.md

@@ -7,7 +7,7 @@ ADB Chat allows you to query data in Autonomous Database using natural language.
 * [NL2SQL](../sql/select-ai-nl2sql.sql)
 * [Select AI RAG](../sql/select-ai-rag.sql)
 
-![ADB Chat APEX app](./select-ai-chat-across-subject-areas.mp4)
+![ADB Chat APEX app](https://github.com/user-attachments/assets/e6db014b-7b6f-416c-b936-d5e4e00d76c7)
 
 
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