Cloud formation YAML script for enabling cluster auto-scaling

I’ve been reading the quick start guide on automating the process of creating a project/cluster via AWS’s cloud formation process. I was looking at the YAML template script and found the ClusterInstanceSize: entry for creating a cluster size.
I was wondering what would be the key-value pair be for enabling the auto-scaling feature?
In the GUI it’s a simple check box with min/max cluster sizes.
Any doc’s on were I can find this info?

Thank you.