link file-as-tag keybinding

[linuxcaffe]

Let's say you had existing image-files/ scans of transaction-related documents, this issue is to request a link-as-tag keybinding, that invokes a (user-definable) file-browser, allows the user to select a file, and then writes that ~/path/to/imagefile.jpg as a transaction tag. In some other small programs, I have seen working examples using, vifm, ranger, mc and I'm sure there are ways to browse-to-file using many other file-managers.

This is related to #20

[hpdeifel]

This would also be solvable with the approach that I outlined in #20 (comment)