Add nix files

flake.nix

@@ -0,0 +1,40 @@
+{
+  description = "pile - personal data indexer";
+
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
+    rust-overlay = {
+      url = "github:oxalica/rust-overlay";
+      inputs.nixpkgs.follows = "nixpkgs";
+    };
+    flake-utils.url = "github:numtide/flake-utils";
+  };
+
+  outputs = { self, nixpkgs, rust-overlay, flake-utils }:
+    flake-utils.lib.eachDefaultSystem (system:
+      let
+        overlays = [ (import rust-overlay) ];
+        pkgs = import nixpkgs { inherit system overlays; };
+
+        rustToolchain = pkgs.rust-bin.fromRustupToolchainFile ./rust-toolchain.toml;
+
+        rustPlatform = pkgs.makeRustPlatform {
+          cargo = rustToolchain;
+          rustc = rustToolchain;
+        };
+
+      in {
+        packages.default = import ./default.nix { inherit pkgs rustPlatform; };
+
+        devShells.default = pkgs.mkShell {
+          buildInputs = [
+            rustToolchain
+            pkgs.pdfium-binaries
+            pkgs.openssl
+            pkgs.pkg-config
+          ];
+
+          LD_LIBRARY_PATH = pkgs.lib.makeLibraryPath [ pkgs.pdfium-binaries ];
+        };
+      });
+}