vimiv plugin for video support

vimiv Video enables support for videos. Videos get listed within vimiv and can be played using an external player like mpv or vlc.

The following video formats are currently supported:

• This plugin requires ffmpeg which needs to be installed.
• Clone this project into $XDG_DATA_HOME/vimiv/plugins/
• Activate vimiv Video by adding video = to the PLUGINS section of $XDG_CONFIG_HOME/vimiv/vimiv.conf.

All your videos are automatically listed in vimiv. To play the selected video, type something like :!mpv %.

If you would like to add support for a new video file format feel free to open a PR with the appropriate additions. In case you do not know how to implement it, you are also welcome to open an issue and submit an adequate sample file.