nix: create initial flake

flake.nix

@@ -0,0 +1,48 @@
+{
+  description = "Lila language";
+
+  inputs = {
+    nixpkgs.url = "github:nixos/nixpkgs?ref=nixos-unstable";
+
+    flake-parts.url = "github:hercules-ci/flake-parts";
+
+    crane.url = "github:ipetkov/crane";
+  };
+
+  outputs =
+    inputs@{ flake-parts, crane, ... }:
+    flake-parts.lib.mkFlake { inherit inputs; } {
+      imports = [
+        ./devShells/flake-module.nix
+      ];
+
+      systems = [
+        "x86_64-linux"
+        "aarch64-linux"
+      ];
+
+      perSystem =
+        { pkgs, lib, ... }:
+        let
+          craneLib = crane.mkLib pkgs;
+
+          pestFilter = path: _type: (builtins.match ".*\.pest$" path) != null;
+          sourceFilter = path: type: (craneLib.filterCargoSources path type) || (pestFilter path type);
+
+          lilac-crate = craneLib.buildPackage ({
+            src = lib.cleanSourceWith {
+              src = ./.;
+              filter = sourceFilter;
+              name = "source";
+            };
+          });
+        in
+        {
+          checks = {
+            inherit lilac-crate;
+          };
+
+          packages.lilac = lilac-crate;
+        };
+    };
+}