Allow more custom filename options

[chris-sanders]

It's good that you allow for custom filenames, but the format I'm using isn't supported currently. I'm looking for something like the UUID option but much shorter. When viewing markdown files in editors that don't do link replacements it makes it very hard to read when filenames are very long. For a note taking application a full UUID is not necessary and I'd like to right-size it.

What I'd like to see is that the pro version allowed you to specify a custom filename so that it's more flexible. If a user could specify the file name format using placeholders they could build a combination that works well for them.

For my specific use case I'd like a short uuid option. I use zk for command line and find their Short UUID to be very nice.

I like GitJournal but I am unsure about introducing another file naming convention into my repository. Hopefully creating a short UUID would be fairly straight forward
just a option to truncate the UUID would be fine I think. If you took it just a little further with user created name templates that would be really nice future proofing.