Merge pull request #21553 from zippy1981/zippy1981-patch-1

Updated docs for using az cli or service principle

website/docs/backends/types/azurerm.html.md

@@ -20,6 +20,7 @@ When authenticating using the Azure CLI or a Service Principal:
 ```hcl
 terraform {
   backend "azurerm" {
+    resource_group_name  = "StorageAccount-ResourceGroup"
     storage_account_name = "abcd1234"
     container_name       = "tfstate"
     key                  = "prod.terraform.tfstate"