Add support for customizing the shortcut used

[FulecoRafa]

Some users may not like the "Shift+CapsLock" shortcut.

Make it possible to register a different shotcut for instantiating a new window.
This can be done through the settings window

In addition, using it in linux with the CapsLock shortcut both starts a new instance and activates capslock, requiring users to hit capslock twice.

[FulecoRafa]

If I may be so bold, I would like to work on this feature myself.

[hiforrest]

I am also quite bothered by the issue of switching cases with Shift+Caps Lock. I really hope this can be fixed soon. Whether it's adding an option to customize the shortcut or changing it to a different key combination, it would greatly alleviate the current inconvenience.

[WanderMzj]

Extract app.asar from ./droppoint/resources, then open shortcut.js in the src folder. Modify the shortcut keys in that file to change the software's shortcuts.