Optional "home" screen when opening app - showing recently opened

[whyboris]

It may be lovely to have the option in settings to enable a "welcome" screen - so rather than opening the last opened hub, VHA will show all the recently-opened hubs.

Preferably letting users add a "cover" image to each hub.

This is a nice-to-have and I may work on this feature after I'm done with the larger projects on the roadmap 👌