Use opentimeline.io format as additional output

[billmetangmo]

Hello @antiboredom

Thanks for your work. It's awesome.
I wanted to export my xml output to Kdenlive but did not succeed.
I think that it's because videogrep can't export vidéo to opentimeline format.
If it's the case, it would be great to support it.

Thanks again,
Regards

[antiboredom]

thanks for this suggestion - I'll definitely look into adding it.

[antiboredom]

Note to self: I think integreting opentimeline.io would also make sense for xml exports, since my current implementation is a bit iffy.