Add example for module usage

Author: rajat-tomar

.gitignore

@@ -1,3 +1,5 @@
 .idea/
 terraform.tfstate*
 .terraform*
+examples/terraform.tfstate*
+examples/.terraform*

examples/main.tf

@@ -0,0 +1,12 @@
+module "gitlab_shell_runner" {
+  source = "../"
+
+  ami_id                    = "ami-0addfae420fd47aab"
+  instance_type             = "t2.micro"
+  instance_count            = 2
+  vpc_security_group_ids    = ["sg-0b0b0b0b0b0b0b0b0"]
+  subnet_id                 = "subnet-0b0e1c4b5b1b1b1b1"
+  gitlab_url                = "https://gitlab.example.com"
+  runner_registration_token = "runner-registration-token-here"
+  ssh_public_key            = "ssh-public-key-here"
+}

examples/variables.tf

@@ -0,0 +1,10 @@
+terraform {
+  required_providers {
+    aws = {
+      source  = "hashicorp/aws"
+      version = "~> 4.49.0"
+    }
+  }
+
+  required_version = "~> 1.3.0"
+}