Update index.html.markdown

Author: brandonc

website/docs/index.html.markdown

@@ -88,7 +88,7 @@ The above snippet using `required_providers` is for Terraform 0.13+; if you are
 
 ```hcl
 provider "tfe" {
-  version = "~> 0.57.0"
+  version = "~> 0.58.0"
   ...
 }
 ```
@@ -101,7 +101,7 @@ For more information on provider installation and constraining provider versions
 provider "tfe" {
   hostname = var.hostname # Optional, defaults to HCP Terraform `app.terraform.io`
   token    = var.token
-  version  = "~> 0.57.0"
+  version  = "~> 0.58.0"
 }
 
 # Create an organization