Add development nix shell

default.nix

@@ -0,0 +1,26 @@
+with import <nixpkgs> { };
+let
+  jekyll_env = pkgs.bundlerEnv {
+    name = "jekyll_env";
+    ruby = pkgs.ruby;
+
+    gemdir = ./.;
+  };
+in pkgs.stdenv.mkDerivation {
+  name = "vampysite";
+
+  buildInputs = with pkgs; [
+    jekyll_env
+    # nokogiri dependencies
+    zlib
+    libiconv
+    libxml2
+    libxslt
+    nodejs-slim
+  ];
+
+  shellHook = ''
+    exec bundle exec jekyll serve --livereload
+  '';
+}
+