Update README.md

Author: KwokHing

README.md

@@ -1,7 +1,7 @@
 ## Automating Infrastructure on Google Cloud with Terraform: Challenge Lab (GSP345) ##
 
-Setup : Create the configuration files
-Make the empty files and directories in Cloud Shell or the Cloud Shell Editor.
+Setup : Create the configuration files <br/>
+Make the empty files and directories in _Cloud Shell_ or the _Cloud Shell Editor_.
 
 ```
 touch main.tf
@@ -21,3 +21,19 @@ touch outputs.tf
 touch variables.tf
 cd
 ```
+
+Add the following to the each _variables.tf_ file, and fill in the GCP Project ID:
+```
+variable "region" {
+ default = "us-central1"
+}
+
+variable "zone" {
+ default = "us-central1-a"
+}
+
+variable "project_id" {
+ default = "<FILL IN PROJECT ID>"
+}
+```
+Add the following to the _main.tf_ file: