v0.6.0

Changes

• Added background music in menus
• Option for cooperative score (average of all players)
• Improved MP3 support
• Reduced number of sentence rating to 5 and more friendly wording
• Show log in-game in development options. And show path to log file.
• Upgrade to Unity 2021.3.4f1
• Fix song select drag action when using right click in song menu
• Fix leading player icon in sing scene switching too much
• Fix lyrics area height when only few lines of text