modify left nav file

Author: yifwang

powerapps-docs/maker/TOC.yml

@@ -137,6 +137,8 @@
         href: ./canvas-apps/add-manage-connections.md
       - name: Connect to SharePoint
         href: ./canvas-apps/connect-to-sharepoint.md
+      - name: Prepare Excel data
+        href: ./canvas-apps/how-to-excel-tips.md
       - name: Delegation
         href: ./canvas-apps/delegation-overview.md
       - name: Delegable data sources
@@ -222,12 +224,12 @@
     - name: Delete a custom entity
       href: ./common-data-service/data-platform-delete-entity.md
   - name: Tutorials
-    items: 
+    items:
     - name: Create a custom entity that has components
       href: ./common-data-service/create-custom-entity.md
   - name: Samples and resources
     href: ./common-data-service/samples-resources.md
   - name: For Developers
     href: ../developer/common-data-service/TOC.yml
 - name: Common Data Model
-  href: ../common-data-model/overview.md    
+  href: ../common-data-model/overview.md