Allow pasting images via Cmd+V

[frzkn]

It would be a huge UX improvement if nchat supported pasting images (e.g., screenshots) directly via Cmd+V / Ctrl+V, similar to how modern messaging apps work. Currently, images must be manually saved and then attached from file this adds friction for the upload operation.

Thanks for building such a slick client!

[d99kris]

Thanks for suggesting, this has been requested before in #185 so I'll close this one as a duplicate. Taking note of the interest though. I've been meaning to take a look at it, it shouldn't be too much work.