re-org and add readme

nixos/flake.nix

@@ -0,0 +1,15 @@
+{
+  description = "A very basic flake";
+
+  inputs = {
+    nixpkgs.url = "github:nixos/nixpkgs?ref=nixos-unstable";
+  };
+
+  outputs = { self, nixpkgs }: {
+
+    packages.x86_64-linux.hello = nixpkgs.legacyPackages.x86_64-linux.hello;
+
+    packages.x86_64-linux.default = self.packages.x86_64-linux.hello;
+
+  };
+}