feat: fixed documentation (#524)

The documentation had a deprecated argument in the home-manager example
by using configuration, this aims to fix that by providing an example of
how to fix it in the current nixos unstable branch(which at the time of
writting is 24.05), through a comment.

Co-authored-by: Dr.Teagle <chrisdockter@proton.me>

README.md

@@ -16,7 +16,10 @@ If you are using flakes to configure your system, add to your nixpkgs overlays a
 
 ```nix
 {
-  inputs.neovim-nightly-overlay.url = "github:nix-community/neovim-nightly-overlay";
+  inputs = {
+    neovim-nightly-overlay.url = "github:nix-community/neovim-nightly-overlay";
+  };
+
   outputs = { self, ... }@inputs:
     let
       overlays = [
@@ -25,10 +28,11 @@ If you are using flakes to configure your system, add to your nixpkgs overlays a
     in
       homeConfigurations = {
         macbook-pro = inputs.home-manager.lib.homeManagerConfiguration {
-          configuration = { pkgs, ... }:
+          modules = [
             {
               nixpkgs.overlays = overlays;
             };
+          ];
         };
       };
 }