Update toc.yml

Added  anew title under concepts, called Security

Author: sameeksha91

articles/sap/monitor/toc.yml

@@ -13,6 +13,10 @@ items:
     items:
     - name: Providers in Azure Monitor for SAP solutions
       href: providers.md
+    - name: Security
+      items:
+      - name: Security baseline
+        href: security-baseline.md
   - name: How-to guides
     items:
     - name: Set up network for Azure Monitor for SAP solutions
@@ -38,4 +42,4 @@ items:
   - name: Reference
     items:
     - name: Data reference for Azure Monitor for SAP solutions
-      href: data-reference.md
+      href: data-reference.md