ssh public key now defined as variable. User can define it under the main deployment file

multiple/shared_modules/variables.tf

@@ -42,8 +42,7 @@ variable "cloudinit_filename" {
 
 variable "ssh_key" {
   description = "SSH authorized keys for cloud-init"
-  type        = list(string)
-  default     = []
+  type        = string
 }
 
 variable "user_data" {