always open new firefox window when opened from launcher

closes #7

home/firefox/default.nix

@@ -1,4 +1,4 @@
-{pkgs, ...}@args:
+{pkgs, lib, ...}@args:
 
 let
   nurpkgs = import (builtins.fetchTarball {url = "https://github.com/nix-community/NUR/archive/master.tar.gz"; sha256 = "1gb3wkmyl6xbs4kval2ml48nlil39853dj62rxfrlk9i2nky2ly4"; }) { inherit pkgs; };
@@ -49,5 +49,24 @@ in
       terminal = false;
       type = "Application";
     };
+
+    xdg.desktopEntries.firefox = lib.mkForce {
+      categories = [ "Network" "WebBrowser" ];
+      exec = "firefox --new-window --name firefox %U";
+      genericName = "Web Browser";
+      icon = "firefox";
+      mimeType = [
+        "text/html"
+        "text/xml"
+        "application/xhtml+xml"
+        "application/vnd.mozilla.xul+xml"
+        "x-scheme-handler/http"
+        "x-scheme-handler/https"
+      ];
+      name = "Firefox";
+      startupNotify = true;
+      terminal = false;
+      type = "Application";
+    };
   };
 }