add hugo

hugo/flake.nix

@@ -0,0 +1,34 @@
+{
+  description = "Good basic flake template";
+  inputs = {
+    nixpkgs.url = "nixpkgs/nixpkgs-unstable";
+    flake-utils.url = "github:numtide/flake-utils";
+  };
+
+  outputs = { self, nixpkgs, flake-utils }:
+     flake-utils.lib.eachDefaultSystem (system:
+       let
+         # Get the SHA by guessing, and nix develop will yell at you
+         # Tarball is much, much faster than the git fetch option
+         # Use https://lazamar.co.uk/nix-versions to find the package version
+         # you need.
+         #
+         # This might be useful at some point, but I don't know when:
+         # https://discourse.nixos.org/t/fixing-error-attribute-currentsystem-missing-in-flake/22386/7
+         hugoPinnedAt108 = import (builtins.fetchTarball {
+          url = "https://github.com/NixOS/nixpkgs/archive/79b3d4bcae8c7007c9fd51c279a8a67acfa73a2a.tar.gz";
+          sha256 = "1lsrlgx4rg2wqxrz5j7kzsckgk4ymvr1l77rbqm1zxap6hg07dxf";
+         }) {
+           inherit system;
+         };
+         systempkgs = nixpkgs.legacyPackages.${system};
+       in
+       {
+         devShells.default = systempkgs.mkShell {
+            buildInputs = with systempkgs; [
+              hugoPinnedAt108.hugo
+            ];
+         };
+       }
+     );
+}