Refactor back to a more modular configuration

modules/home-manager/cli/fzf.nix

@@ -0,0 +1,21 @@
+{ config, lib, ... }:
+
+with lib;
+
+let
+  cfg = config.homeManagerModules.cli.fzf;
+in
+{
+  options.homeManagerModules.cli.fzf.enable = mkEnableOption "Enable fzf";
+
+  config = mkIf cfg.enable {
+    programs.fzf = {
+      enable = true;
+      enableZshIntegration = true;
+    };
+
+    home.sessionVariables = {
+      FZF_DEFAULT_OPTS = "--reverse";
+    };
+  };
+}