docs: add developer-workflow.org and language examples

Complete workflow guide for Perl, Python, Go, Ansible, Terraform, Podman.
Includes working example files in examples/ directory.

examples/terraform/variables.tf

@@ -0,0 +1,18 @@
+# variables.tf — Input variables for the Terraform demo.
+
+variable "greeting_message" {
+  description = "Message to write to the output file"
+  type        = string
+  default     = "Hello from Terraform!"
+}
+
+variable "environment" {
+  description = "Deployment environment name"
+  type        = string
+  default     = "dev"
+
+  validation {
+    condition     = contains(["dev", "staging", "prod"], var.environment)
+    error_message = "Environment must be dev, staging, or prod."
+  }
+}