Have an additional_datastore option to go with additional_disk_size_gb?

[vchung-nz]

Since there is an additional_disk_size_gb bootstrap option, does it make sense to have an optional additional_datastore option as well? eg for VM with additional disks on higher storage tier.

Something like:

with_machine_options :bootstrap_options => {
  ...
  additional_datastore: ["tier_one_ds", "tier_two_ds"],
  additional_disk_size_gb: [50,20],
  ...

If undefined, then the behaviour is unchanged: requires datastore to be defined instead.