Restructured two articles in TOCs

Author: v-smandalika

…er-xdr/pilot-deploy-defender-endpoint.md …dpoint/pilot-deploy-defender-endpoint.mddefender-xdr/pilot-deploy-defender-endpoint.md renamed to defender-endpoint/pilot-deploy-defender-endpoint.md defender-xdr/pilot-deploy-defender-endpoint.md renamed to defender-endpoint/pilot-deploy-defender-endpoint.md

@@ -39,6 +39,8 @@
      items:
      - name: Get started with Microsoft Defender for Office 365
        href: mdo-deployment-guide.md
+     - name: Pilot and deploy Microsoft Defender for Office 365
+       href: pilot-deploy-defender-office-365
      - name: Step 1 - Configure email authentication
        items:
        - name: About email authentication