Linux support

[clearlysid]

Windows and macOS are supported at the moment, but Linux is not.

There are 2 blockers for Linux:

1. Our encoding library henx does not have Linux support yet.
2. The Tauri webview does not support video playback in the browser so preview wouldn't work.

I'm fairly confident that there will be workarounds for both of these, but haven't gotten the time to tinker with Linux much so far. Happy to help out or guide someone else in this quest if needed.