[Feature Request] Add custom shortcut keys to control the volume and retrieve the current display volume value

[CooperZhuang]

The issue arises when a monitor is connected to both Mac and Windows operating systems, and is used for audio output. On a Mac, you can only adjust the volume by changing the monitor's volume setting. When switching back to Windows, this causes a mismatch between the software volume level and the monitor volume level. To address this, it would be helpful if Twinkle Tray could automatically retrieve the volume value. Additionally, to maintain consistent volume levels when using both Mac and Windows, I prefer to adjust the monitor's volume rather than the system volume. If it were possible to set the volume using hotkeys, it would be even more convenient.