Set default zone for multiline step.

Co-authored-by: jmhbnz <mail@jamesblair.net>

README.org

@@ -141,6 +141,9 @@ Next up we need to install [[https://docker.com][Docker]] on the newly created v
 By default the virtual machine operating system for the vm we created on GCP is [[https://debian.org][Debian]]. There are instructions for installing Docker on a debian machine [[https://docs.docker.com/engine/install/debian/#install-using-the-repository][here]].
 
 #+begin_src bash :shebang #!/bin/bash :tangle 5-install-docker.sh
+# Set default zone
+gcloud config set compute/zone australia-southeast1-a
+
 # Retrieve the vm name
 export gcp_machine_name=$(gcloud compute instances list --limit=1 --format='value(name.basename())')