v5.9.0.0-beta

• Fix startup without media file not working with gpu-api=vulkan.
• Fix keyboard layout change not working.
• Fix multi monitor setup with different DPI values not working.
• Fix config editor handling keep-open and keep-open-pause incorrectly.
• New mpv.net specific option keep-open-exit added. If set to yes and
  keep-open is set to no, mpv.net exits after the last file ends.
• New playlist-add command added to change the playlist position,
  jumps to the other end when the beginning or end is reached.
  Ctrl+F11 goes 10 positions backward.
  Ctrl+F12 goes 10 positions forward.
• libmpv zhongfly 2022-05-07