docs: rewrite README with structured overview and quick start guide

Replaces the minimal project description with a comprehensive README
including a component overview table, quick start instructions, common
Ansible operations, and links to detailed documentation. Aligns with
Red Panda Approval™ standards.

terraform/versions.tf

@@ -0,0 +1,13 @@
+terraform {
+  required_version = ">= 1.0"
+  
+  required_providers {
+    incus = {
+      source  = "lxc/incus"
+    }
+  }
+}
+
+provider "incus" {
+  # Configuration will be read from environment or default socket
+}