TUXEDO Backlight Control v0.8

Release notes

• Fancier icon (for better display on dark/light backgrounds)
• Added brightness CLI command, use as backlight brightness <0-255>
• Added bash autocompletion!
• Added version indicator to UI title bar
• Fixed: only add color_extra controls if the keyboard supports it 01d435e
• Fixed: potential errors on writing back tuxedo_keyboard params
• Cleaned up Python code