Template : Add FHSEnv.nix thanks to Александр Бантьев.

document/template/FHSEnv.nix

@@ -0,0 +1,20 @@
+{
+	description = "";
+
+	inputs = {
+		nixpkgs.url = "github:nixos/nixpkgs/nixos-unstable";
+	};
+
+	outputs = { self, nixpkgs } @inputs: let
+		system = "x86_64-linux";
+		lib    = nixpkgs.lib;
+		pkgs   = nixpkgs.legacyPackages.${system};
+	in {
+		devShells.${system} = {
+			default = with pkgs; (buildFHSEnv {
+				name = "FHSEnv";
+				targetPkgs = pkgs: with pkgs; [ ];
+			}).env;
+		};
+	};
+}