Market Problem Template descriptions and documentation.

Market Problem

• As an OpenShift cluster administrator, I want to provide instance type fallbacks in MachineSets, so that if my cloud provider doesn't have the initial instance type available I will still have fallback instance types to ensure desired resource requirements.

Expected Outcomes

• When creating a MachineSet, customers would like to define their preferred instance type, while still being able to provide fallback instance type options
• Cloud providers don't always, reliably have specific instance type capacity in a given region, and so it would be helpful to have fallback options available for a MachineSet to provision
• This is typically more common on AWS, however I suspect other cloud providers have this problem

Effect

• AWS EKS provides this to their customers as "node group capacity types": https://docs.aws.amazon.com/eks/latest/userguide/managed-node-groups.html#managed-node-group-capacity-types