Feature request: Make it possible to run a dedicated single purpose Database for important Apps.

[holm]

It would be a nice feature to make a decision if an app uses the central database or its own container. in my docker-compose stacks i mostly have single purpose database containers for services like synapse. it is a question of taste, but i like single purpose database containers more than centralized storage.

There are Apps, where it makes no sense to run a dedicated Database Server. But on Things like Synapse or Mastodon it makes sense to split it from other Apps. Even in case of need for performing tweaks.