Add desktopName to package.json

[PerchunPak]

Since Electron 41, the WM class is set differently. Instead of using name from package.json, it now looks at desktopName with a fallback to executable name (which is usually electron, because equibop is a shell script wrapper)

WM class is what you see in hyprctl clients or similar commands:

Window 559ff5695040 -> Discord:
        mapped: 1
        hidden: 0
        at: 11,60
        size: 1898,1009
        workspace: 3 (3)
        floating: 0
        monitor: 0
        class: electron      # <- here
        title: Discord
        initialClass: electron
        initialTitle: Discord
        pid: 209204
        xwayland: 0
        pinned: 0
        fullscreen: 0
        fullscreenClient: 0
        overFullscreen: 0
        grouped: 0
        tags:
        swallowing: 0
        focusHistoryID: 9
        inhibitingIdle: 0
        xdgTag:
        xdgDescription:
        contentType: none
        stableID: 18000065

See also NixOS/nixpkgs#505078

P.S. This is not a Nix-specific issue, Flatpak version is also affected