Update README.md

Author: Nowaker

README.md

@@ -13,7 +13,7 @@ Requirements
 -	[Terraform](https://www.terraform.io/downloads.html) 0.12.x
 -	[Go](https://golang.org/doc/install) 1.11 (to build the provider plugin)
 
-Using the Provider
+Using the Provider (TF 0.13+)
 ----------------------
 
 ```hcl