GroundZero Resource Pack v40 - Rotten Horizon Main Menu Music

Added:
- assets/minecraft/sounds/music/menu/rotten_horizon.ogg

Changed:
- assets/minecraft/sounds.json
- Overrides Minecraft's menu music event:
  music.menu

Sound:
- Rotten Horizon
- Duration: 400.40 seconds
- OGG Vorbis, streamed

Important:
- This replaces the vanilla Minecraft main menu music while this resource pack is enabled.
- It only plays if the client has this updated resource pack loaded.
- Minecraft menu music may not start instantly every time; it follows Minecraft's normal menu music timing.
