add nix build files

default.nix

@@ -0,0 +1,25 @@
+# default.nix
+let
+  pkgs = import <nixpkgs> {};
+in
+pkgs.stdenv.mkDerivation rec {
+  pname = "kte";
+  version = "0.1.0";
+
+  src = ./.;
+
+  nativeBuildInputs = [ pkgs.cmake ];
+  buildInputs = [ pkgs.ncurses ];
+
+  cmakeFlags = [
+    "-DCURSES_NEED_NCURSES=TRUE"
+    "-DCURSES_NEED_WIDE=TRUE"
+  ];
+
+  meta = with pkgs.lib; {
+    description = "A small terminal text editor";
+    license = licenses.mit;
+    platforms = platforms.linux;
+    mainProgram = "kte";
+  };
+}