add basic nix flake template

flake.nix

@@ -85,6 +85,10 @@
 
       # Templates for starting other projects quickly
       templates = {
+        basic = {
+          path = ./templates/basic;
+          description = "Basic program template";
+        };
         poetry = {
           path = ./templates/poetry;
           description = "Poetry template";

templates/basic/.envrc

@@ -0,0 +1 @@
+use flake

templates/basic/flake.lock

@@ -0,0 +1,27 @@
+{
+  "nodes": {
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1659803779,
+        "narHash": "sha256-+5zkHlbcbFyN5f3buO1RAZ9pH1wXLxCesUJ0vFmLr9Y=",
+        "owner": "nixos",
+        "repo": "nixpkgs",
+        "rev": "f44884060cb94240efbe55620f38a8ec8d9af601",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nixos",
+        "ref": "nixos-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "nixpkgs": "nixpkgs"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}

templates/basic/flake.nix

@@ -0,0 +1,19 @@
+{
+  description = "Basic project";
+  inputs.nixpkgs.url = "github:nixos/nixpkgs/nixos-unstable";
+  outputs = { self, nixpkgs }:
+    let
+      forAllSystems = nixpkgs.lib.genAttrs [
+        "x86_64-linux"
+        "x86_64-darwin"
+        "aarch64-linux"
+        "aarch64-darwin"
+      ];
+    in {
+      devShells = forAllSystems (system:
+        let pkgs = import nixpkgs { inherit system; };
+        in {
+          default = pkgs.mkShell { buildInputs = with pkgs; [ nixfmt ]; };
+        });
+    };
+}