feat: add ssh_key variable support to cloud-init module

multiple/shared_modules/variables.tf

@@ -39,6 +39,13 @@ variable "cloudinit_filename" {
   type        = string
   default     = "commoninit.iso"
 }
+
+variable "ssh_key" {
+  description = "SSH authorized keys for cloud-init"
+  type        = list(string)
+  default     = []
+}
+
 variable "user_data" {
   description = "User data for cloud-init"
   type        = string