JSON-Based Shortcut Configuration

[Trikooo]

Please add support for editing and managing keyboard shortcuts through a JSON file, similar to how it's done in VSCode.

This would make it much easier to back up, restore, and share shortcut configurations—especially since Firefox accounts currently don't sync custom shortcuts. Every time I reinstall or use a new device, I have to manually reassign everything, which is time-consuming and error-prone.

A simple import/export system using JSON would solve this problem elegantly.