services: move .nix files into their own dirs

modules/services/locate/module.nix

@@ -0,0 +1,20 @@
+{
+  config,
+  lib,
+  pkgs,
+  ...
+}: let
+  cfg = config.modules.services.locate;
+  inherit (lib.modules) mkIf;
+  inherit (lib.options) mkEnableOption;
+in {
+  options.modules.services.locate.enable = mkEnableOption "Locate service";
+  config = mkIf cfg.enable {
+    environment.systemPackages = [pkgs.plocate];
+    services.locate = {
+      enable = true;
+      interval = "hourly";
+      package = pkgs.plocate;
+    };
+  };
+}