Cleanup: moved things from configuration.nix and home.nix to new modules

modules/home-manager/gtk.nix

@@ -0,0 +1,16 @@
+{
+  config,
+  pkgs,
+  ...
+}: {
+  # gtk config
+  gtk.theme = {
+    enable = true;
+    Gruvbox-GTK-Theme-BL-MB = {
+      enable = true;
+      name = "Gruvbox-GTK-Theme-BL-MB";
+      package = pkgs.gruvbox-gtk-theme;
+    };
+  };
+  # to resolve this https://wiki.nixos.org/wiki/Home_Manager#I_cannot_set_GNOME_or_Gtk_themes_via_Home_Manager
+}

modules/home-manager/ssh.nix

@@ -20,4 +20,9 @@
     };
   };
   services.ssh-agent.enable = true;
+  home.file.".ssh/config".text = ''
+    Host *
+      AddKeysToAgent yes
+      IdentityFile ~/.ssh/id_ed25519
+  '';
 }

modules/nixos/nixUtils.nix

@@ -0,0 +1,18 @@
+{
+  config,
+  pkgs,
+  pkgs-unstable,
+  libs,
+  inputs,
+  ...
+}: {
+# Garbage collector of generations
+  nix.gc = {
+    automatic = true;
+    dates = "weekly";
+    options = "--delete-older-than 7d"; # every week delete generations older than a month
+  };
+  # nixpkgs-review crashed my laptop multiple times.
+  nix.settings.max-jobs = 2;
+  nix.settings.cores = 2;
+}