Investigate and document appliance password recovery

[andrewtchin]

User Statement:

As a user I want to login to an appliance I forgot the password to.

Details: Figure out how we want to do handle this https://github.com/vmware/photon/blob/master/docs/photon-os-troubleshooting-guide.md#resetting-a-lost-root-password

Acceptance Criteria:

• [ ] Update to password setting from ovfenv, if needed
• [ ] documentation