update user_data to enable nginx

2-simple-example/README.md

@@ -17,6 +17,7 @@ resource "aws_instance" "test_ami" {
   user_data = <<-EOF
               #!/bin/bash
               sudo dnf install -y nginx
+              sudo systemctl enable nginx
               sudo systemctl start nginx
               EOF
 }
@@ -52,6 +53,12 @@ Embedded in there you'll see something liek this ```instance_public_ip``` thats
 ![Default nginx page](./img/webpage.png)
 (I'm of course in dark mode, don't worry if yours is white with black text!)
 
+Right we now have our basic stack to work with. Everything else we do will be to update this stack, so **don't destroy** it just yet
+
+#### Introducing variables
+
+Right this is great and all but what if we want to make it easy to change things, such as the region we are deploying in or the size of the instance we are running. This is where variables make it easy, and as an added advantage we can create variable files for different environments with different values in them.
+
 
 
 2. Validate

2-simple-example/code/main.tf

@@ -49,6 +49,7 @@ resource "aws_instance" "test_ami" {
   user_data = <<-EOF
               #!/bin/bash
 	      sudo dnf install -y nginx 
+              sudo systemctl enable nginx
               sudo systemctl start nginx
               EOF
 }