📦 Created config files with common code

- Created common.nix for various configs
- Created theme.nix for theme related configs
- Moved some code to more logical files
- Moved some standalone files into nix multiline strings, in order to
  inject data

modules/gnome/nautilus.nix

@@ -1,13 +1,15 @@
 { pkgs, ... }:
-
+let
+  common = import ../../common.nix;
+in
 {
   environment.systemPackages = with pkgs; [
     nautilus
-    ffmpegthumbnailer
+    ffmpegthumbnailer # Thumbnails
   ];
 
   programs.nautilus-open-any-terminal = {
     enable = true;
-    terminal = "kitty";
+    terminal = common.terminal;
   };
 }