Merge infra and k3 into one directory again

Since I don't have multiple terraform steps anymore it simply doesn't
make sense to me anymore to split all tasks into separate folders.
Instead I try to be as clear as possible in the README to make it easy
to follow the structure in the future without too much headache.

versions.tf

@@ -0,0 +1,31 @@
+terraform {
+  required_providers {
+    hetznerdns = {
+      source  = "timohirt/hetznerdns"
+      version = "2.2.0"
+    }
+    hcloud = {
+      source  = "hetznercloud/hcloud"
+      version = "1.50.0"
+    }
+    random = {
+      source  = "hashicorp/random"
+      version = "3.7.1"
+    }
+    external = {
+      source  = "hashicorp/external"
+      version = "2.3.4"
+    }
+  }
+}
+
+provider "hetznerdns" {
+  apitoken = var.hetzner_dns_apitoken
+}
+
+provider "hcloud" {
+  token = var.hetzner_cloud_apitoken
+}
+
+provider "random" {}
+provider "external" {}