modify toc.yaml to add a table of content entry

Author: ChenJieting

articles/machine-learning/toc.yml

@@ -656,6 +656,8 @@
               href: ./prompt-flow/tools-reference/vector-db-lookup-tool.md
             - name: SERP API tool
               href: ./prompt-flow/tools-reference/serp-api-tool.md
+            - name: Troubleshoot Guidance
+              href: ./prompt-flow/tools-reference/troubleshoot-guidance.md
     - name: Retrieval Augmented Generation (RAG)
       items:
         - name: What is RAG