Flag for filtering by “not tagged”

[jotaen]

The CLI allows to filter for entries by certain tags, e.g. --tag=sports. However, what’s not possible is to filter for entries which aren’t tagged, e.g. via something like --no-tag or --not-tagged.

I think a “not tagged” filter could generally be added to klog. However, I also feel that the capabilities to filter via CLI flags are limited by design. So I’m not sure whether it’s a good idea to keep adding more and more flags, or whether it might be a better approach to e.g. work on a more powerful querying mechanism to meet more sophisticated use-cases/needs.