Create workflow to containarize and publish shiny-apps

[jenast]

Several shiny apps in NINA are containerized already. However, we (might?) need some infrastructure to publish them, as well as some tutorial on how to containerize an app.

You might be working on this already, but I'll start this issue to document any progress. Are you willing to work on this?

We have some money to be spent in 2024, if needed.