docs: update provider example to use v0.5.0

Updates the provider example version constraint from 0.1.0 to ~> 0.5.0
to reflect the current stable version with plan modifier fixes.

Author: Verolop

examples/provider/provider.tf

@@ -2,7 +2,7 @@ terraform {
   required_providers {
     authzed = {
       source  = "authzed/authzed"
-      version = "0.1.0"
+      version = "~> 0.5.0"
     }
   }
 }