[Feature]: Possibility to run custom script before and after virtual machine run

[xlazom00]

Is your proposal related to a problem?

I want to fully automate Windows in docker + update to latest version + debloat windows.
Installation of windows is fully automate. I need to auto update process. For that purpose I am installing openssh server from OEM directory.
And I have separate script that will connect to windows and call windows update and will run whole debloat process.

So I would like to have a option to hook my script somewhere.

Describe the solution you'd like.

Possibility to bind directory with files for prevmrun and postvmrun. Or some better something similar.
We can also use postvmrun for shrining vm image.

Describe alternatives you've considered.

I can do it manually.

Additional context

No response

[xlazom00]

related to #784

[kroese]

I now added a feature where you can execute a script during startup:

volumes:
  - ./custom.sh:/run/start.sh