add clan flake-parts module

Add clan flakeRef

flake.nix

@@ -10,6 +10,10 @@
     agenix-shell.url = "github:aciceri/agenix-shell";
     agenix-shell.inputs.nixpkgs.follows = "nixpkgs";
     devenv.url = "github:hercules-ci/devenv/flake-module";
+    clan-core.url = "https://git.clan.lol/clan/clan-core/archive/main.tar.gz";
+    clan-core.inputs.treefmt-nix.follows = "treefmt-nix";
+    clan-core.inputs.flake-parts.follows = "flake-parts";
+    clan-core.inputs.nixpkgs.follows = "nixpkgs";
     devenv.inputs.nixpkgs.follows = "nixpkgs";
     devshell.url = "github:numtide/devshell";
     devshell.inputs.nixpkgs.follows = "nixpkgs"; # https://github.com/NixOS/nix/issues/7730
@@ -103,6 +107,20 @@
           '';
         };
 
+        clan = {
+          title = "clan";
+          baseUrl = "https://git.clan.lol/clan/clan-core/src/branch/main";
+          flakeRef = "https://git.clan.lol/clan/clan-core/archive/main.tar.gz";
+          attributePath = [ "flakeModules" "default" ];
+          intro = ''
+            [Clan](https://clan.lol) is a multi-machine configuration framework for NixOS with a focus on
+            VPNs, automatic secret and backup management.
+
+            Checkout our [documentation](https://docs.clan.lol/manual/flake-parts/) for more information on using the flake-parts module and
+            also our [getting started guide](https://docs.clan.lol/getting-started) for general information.
+          '';
+        };
+
         devenv = {
           title = "devenv";
           baseUrl = "https://github.com/cachix/devenv/blob/main";