Added flake.nix

flake.nix

@@ -0,0 +1,17 @@
+{
+  description = "Lemmy running in a container";
+
+  inputs = {
+    nixpkgs.url = "nixpkgs/nixos-23.11";
+    arion.url = "github:hercules-ci/arion";
+  };
+
+  outputs = { self, nixpkgs, arion, ... }: {
+    nixosModules = rec {
+      default = lemmyContainer;
+      lemmyContainer = { ... }: {
+        imports = [ arion.nixosModules.arion ./lemmy-container.nix ];
+      };
+    };
+  };
+}