Add Nix flake and improve derivation

This adds a Nix flake to the repo as well as updates the derivation so
that it includes `lzip` as a dependency

package.nix

@@ -0,0 +1,32 @@
+{ lib,
+  stdenvNoCC,
+  lzip,
+  python3,
+  makeWrapper }:
+let
+  wrappedPath = lib.makeBinPath [ lzip ];
+in stdenvNoCC.mkDerivation {
+  name = "waydroid_script";
+
+  buildInputs = [
+    (python3.withPackages(ps: with ps; [ tqdm requests inquirerpy ]))
+  ];
+
+  nativeBuildInputs = [
+    makeWrapper
+  ];
+
+  src = ./.;
+
+  postPatch = ''
+    patchShebangs main.py
+  '';
+
+  installPhase = ''
+    mkdir -p $out/libexec
+    cp -r . $out/libexec/waydroid_script
+    mkdir -p $out/bin
+    makeShellWrapper $out/libexec/waydroid_script/main.py $out/bin/waydroid_script \
+      --prefix PATH : "${wrappedPath}"
+  '';
+}