Added link to Azure roles doc

Author: RoseHJM

articles/lab-services/administrator-guide.md

@@ -224,6 +224,8 @@ When you're assigning roles, it helps to follow these tips:
 - Ordinarily, only administrators should be members of a lab plan Owner or Contributor role. The lab plan might have more than one Owner or Contributor.
 - To give educators the ability to create new labs and manage the labs that they create, you need only assign them the Lab Creator role.
 - To give educators the ability to manage specific labs, but *not* the ability to create new labs, assign them either the Owner or Contributor role for each lab that they'll manage. For example, you might want to allow a professor and a teaching assistant to co-own a lab.
+- 
+For more detail about the permissions assigned to each role, see [Azure built-in roles](/azure/role-based-access-control/built-in-roles#lab-creator)
 
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