chore(variables): update environment variable descriptions and default values

Author: sh1un

variables.tf

@@ -3,11 +3,14 @@ variable "aws_region" {
   description = "AWS region where the Lambda warmer will be deployed."
 }
 
+
+
+# Optional variables
 variable "environment" {
-  description = "Current environment: prod(ap-northeast-1)/dev(us-east-1)/local-dev(us-west-2), default dev(us-east-1)."
+  description = "Current environment, e.g. dev, stage, prod. the default value is 'default'."
+  default     = "default"
 }
 
-# Optional variables
 variable "lambda_function_name" {
   description = "Name of the Lambda function used for prewarming."
   default     = "lambda-warmer"