feat: introduce non-flake compatibility

Signed-off-by: Raito Bezarius <masterancpp@gmail.com>

default.nix

@@ -0,0 +1,10 @@
+(import
+  (
+    let lock = builtins.fromJSON (builtins.readFile ./flake.lock); in
+    fetchTarball {
+      url = lock.nodes.flake-compat.locked.url;
+      sha256 = lock.nodes.flake-compat.locked.narHash;
+    }
+  )
+  { src = ./.; }
+).defaultNix

flake.lock

@@ -1,5 +1,18 @@
 {
   "nodes": {
+    "flake-compat": {
+      "locked": {
+        "lastModified": 1714705744,
+        "narHash": "sha256-SsaS620K6QZVCOUqcWU/sHEkipnsJcqslfrU9oko+f4=",
+        "rev": "5adafc5bfbb5b1df965df8ade18b1b0ce00a418e",
+        "type": "tarball",
+        "url": "https://git.lix.systems/api/v1/repos/lix-project/flake-compat/archive/5adafc5bfbb5b1df965df8ade18b1b0ce00a418e.tar.gz"
+      },
+      "original": {
+        "type": "tarball",
+        "url": "https://git.lix.systems/api/v1/repos/lix-project/flake-compat/archive/main.tar.gz"
+      }
+    },
     "nixpkgs": {
       "locked": {
         "lastModified": 0,
@@ -14,6 +27,7 @@
     },
     "root": {
       "inputs": {
+        "flake-compat": "flake-compat",
         "nixpkgs": "nixpkgs"
       }
     }

flake.nix

@@ -5,6 +5,7 @@
  */
 {
   description = "A wireguard network creation tool";
+  inputs.flake-compat.url = "https://git.lix.systems/api/v1/repos/lix-project/flake-compat/archive/main.tar.gz";
   outputs = { self, nixpkgs, ... }:
   let
     forAllSystems = nixpkgs.lib.genAttrs [ "x86_64-linux" "aarch64-linux" ];