Support multiple tomes

[mborst]

I have the feeling that users might want to have multiple tomes, e.g. one for work, one for private stuff. The later this is added, the more painful it becomes.

What does that mean?

• A list of tomes with names instead of one tome in the configuration
• Write commands support setting the tome
• Read commands support selecting in which tomes to search
• 'set-default' command that allows setting a persistent default

[gesundkrank]

I think it would add a bit too much complexity. At least at this early stage of the project.

[mborst]

That's kind of why I want to add it now, I think we need to figure out how this would be comfortably done in golang. Ideally, it does not add that much for implementation of additional commands, but I'd like to find out how we can achieve that and what the interfaces have to look like.