ACCESS-ESM1.5: ACCESS-NRI flagship release plans

@tiloz mentioned at the ESM Working Group meeting that it would be good to have an emissions driven Pre-Industrial (PI) control to match the emissions driven historical that is planned.

@tiloz also pointed out there are payu based experiments developed by others in the community. It would be good to have an accounting of all that is currently available in case there are some that would be good, and simple, candidates for the ACCESS-NRI to adopt and support.