Moved KQL to inside Concepts

Author: yossi-karp

articles/data-explorer/toc.yml

@@ -25,17 +25,17 @@
     href: ingest-data-no-code.md  
   - name: Visualize data in Power BI
     href: visualize-power-bi.md  
-- name: Kusto Query Language
-  items:
-  - name: Quick reference guide
-    href: quick-reference-guide.md
-  - name: Concepts
+- name: Concepts
   items:
   - name: Data ingestion
     items:  
     - name: Data ingestion overview
       displayName: pipelines, connectors, plugins, Python, .NET, Java, Node, REST
       href: ingest-data-overview.md
+    - name: Kusto Query Language
+    items:
+      - name: Quick reference guide
+        href: quick-reference-guide.md
   - name: Data visualization overview
     href: viz-overview.md
   - name: Security overview