(Azure CXP) Add technical note.

This is as per MicrosoftDocs/azure-docs#54917

Added the following note on line 138 , 139 

> [!Note]
  > The "templateId": "GUID" is an optional parameter being sent in the body depending on requirement. If you have a requirement for creating multiple different custom role with common parameters , it is best to create a template and define a templateId . You can generate a templateId beforehand using the powershell cmdlet (New-Guid).Guid . 

Fixes MicrosoftDocs/azure-docs#54917

-------
cc: @curtand

Author: shashishailaj

articles/active-directory/users-groups-roles/roles-create-custom.md

@@ -135,6 +135,9 @@ $roleAssignment = New-AzureADMSRoleAssignment -ResourceScope $resourceScope -Rol
    }
     ```
 
+  > [!Note]
+  > The "templateId": "GUID" is an optional parameter being sent in the body depending on requirement. If you have a requirement for creating multiple different custom role with common parameters , it is best to create a template and define a templateId . You can generate a templateId beforehand using the powershell cmdlet (New-Guid).Guid . 
+
 1. Create the role assignment.
 
     HTTP request to create a custom role definition.
@@ -155,6 +158,7 @@ $roleAssignment = New-AzureADMSRoleAssignment -ResourceScope $resourceScope -Rol
    }
     ```
 
+
 ## Assign a custom role scoped to a resource
 
 Like built-in roles, custom roles are assigned by default at the default organization-wide scope to grant access permissions over all app registrations in your organization. But unlike built-in roles, custom roles can also be assigned at the scope of a single Azure AD resource. This allows you to give the user the permission to update credentials and basic properties of a single app without having to create a second custom role.