[Starlingx-discuss] Virtual Install guide updates

We've discussed two approaches to updating the StarlingX virtual install documentation on the weekly stx-docs calls. Options are: * Include chunks of content from the bare-metal docs in the existing virtual docs, maintaining only one copy in the source. * Remove the Virtual guide and include that content in tabs in the existing base metal guide where they differ from bare metal: [Virtual tab | Bare metal tab] These tabs will need to be conditionalized, testing indicates this will work. Soliciting opinions here on which approach to take. The tabbed approach will involve adding a new plugin.