librewolf: init (#679)

Link: https://github.com/danth/stylix/pull/679

Co-authored-by: Daniel Thwaites <danth@danth.me>
Co-authored-by: NAHO <90870942+trueNAHO@users.noreply.github.com>

modules/firefox/hm.nix

@@ -1,3 +1,6 @@
+# Consider also updating the LibreWolf module when updating this module,
+# as they are very similar.
+
 { config, lib, ... }:
 
 let

modules/librewolf/hm.nix

@@ -0,0 +1,31 @@
+# This module is a copy of the Firefox module.
+
+{ config, lib, ... }:
+
+let
+  profileSettings = {
+    settings = {
+      "font.name.monospace.x-western" = config.stylix.fonts.monospace.name;
+      "font.name.sans-serif.x-western" = config.stylix.fonts.sansSerif.name;
+      "font.name.serif.x-western" = config.stylix.fonts.serif.name;
+    };
+  };
+  makeProfileSettingsPair = profileName:
+    lib.nameValuePair profileName profileSettings;
+in {
+  options.stylix.targets.librewolf = {
+    enable =
+      config.lib.stylix.mkEnableTarget "Librewolf" true;
+
+    profileNames = lib.mkOption {
+      description = "The Librewolf profile names to apply styling on.";
+      type = lib.types.listOf lib.types.str;
+      default = [ ];
+    };
+  };
+
+  config = lib.mkIf (config.stylix.enable && config.stylix.targets.librewolf.enable) {
+    programs.librewolf.profiles = lib.listToAttrs
+      (map makeProfileSettingsPair config.stylix.targets.librewolf.profileNames);
+  };
+}