Update reference TOC

Author: Microsoft Graph DevX Tooling

api-reference/beta/toc/files/toc.yml

@@ -448,3 +448,5 @@ items:
     href: ../../resources/filestoragecontainertyperegistrationsettings.md
   - name: File storage container type settings
     href: ../../resources/filestoragecontainertypesettings.md
+  - name: Share point group identity
+    href: ../../resources/sharepointgroupidentity.md