refactoring to more granular flakes and modules

flakes/common/nix_modules/jetbrains_font.nix

@@ -0,0 +1,33 @@
+{
+  pkgs,
+  ...
+}:
+let
+  hasNewJetbrainsMono =
+    if builtins.hasAttr "nerd-fonts" pkgs then
+      builtins.hasAttr "jetbrains-mono" pkgs."nerd-fonts"
+    else
+      false;
+
+  jetbrainsMonoFont =
+    if hasNewJetbrainsMono then
+      pkgs.nerd-fonts.jetbrains-mono
+    else
+      (pkgs.nerdfonts.override { fonts = [ "JetBrainsMono" ]; });
+in
+{
+  config = {
+    fonts.fontconfig.enable = true;
+
+    fonts.packages = [
+      jetbrainsMonoFont
+    ]
+    # TODO verify if these are needed/working
+    # ++ (with pkgs; [
+    #   ipafont
+    #   kochi-substitute
+    #   noto-fonts-cjk-sans # Or another CJK font
+    # ])
+    ;
+  };
+}