Esteemed maintainers,

Currently, Kdenlive throws errors regarding 2 things as soon as it starts:
1. ffmpeg, ffprobe and ffplay not being found
2. breeze icon theme not being found

Attached is a patch that addresses the first of these issues.

ffmpeg is added to the input of the package, and the final binary is wrapped to include the ffmpeg binaries in it's PATH.

As for issue #2, I have sent in (rough) patches that adds the full breeze-icon theme to guix distribution which should be merged to the tree before another patch can be sent.

Thank you.