Feature Request: Add a single track by default at launch

[bnlcas]

Hey there, I am looking into using Mini-Cut for some personal video editing work.
A small issue that has got me the last few times that I have started this program is the fact that one needs to manually add a track in order to do anything. It feels like the first track should be added by default since you need at least one track to do anything. I poked through the code base and I found that adding the following line to
MiniCutState.swift initialized the interface with a single track:

init() { self.timeline.tracks.append(Track(name: "Track \(self.timeline.tracks.count + 1)")) }

Please let me know if there is interest in adding such a feature let and I can submit a pull request.

[bnlcas]

Basically this:
https://github.com/bnlcas/mini-cut/tree/add-single-track-on-launch