nixos flake

[JJJHolscher]

Hi, Here is a flake.nix for nixos users.

I'm not making this a full pull request, because

1. this flake is fully written by an LLM
2. I'm only testing this on gnome with fcitx5, though the flake also supports ibus (in theory)

In case you're using fcitx5, all you have to do is download the flake.nix attached to this message, add it to your system's flake's inputs and use it as an addon to fcitx5 like so:

{inputs, ...}: {
  i18n.inputMethod = {
    fcitx5 = {
      addons = [
        inputs.im-emoji-picker.packages.x86_64-linux.fcitx5-im-emoji-picker
      ];
    };
  };

  # unfortunately qt tries xcb regardles of XDG_SESSION_TYPE=wayland
  environment.sessionVariables = {
    QT_QPA_PLATFORM = "wayland";
  };
}