Add folder "video_frames" to program location, it needs it or it seg faults

[no1453]

The program voyager.cpp doesn't create this directory, it just expects it to be there. Perhaps add the empty directory "video_frames" to the root of the repository. I had to decipher quite a bit of code to figure out it needed this directory. But, great project, thanks for it. Edit: also the directory "waveforms" is expected by waveforms.cpp.