README: suggest the use of the packaged script

Without this change users will be running the script directly and might encounter errors as they are using the script unpackaged without its dependencies.

Author: Kranzes

README.md

@@ -23,7 +23,7 @@ our [example](https://github.com/numtide/nixos-remote-examples/blob/9768e438b146
 Afterwards you can just run:
 
 ```
-./nixos-remote root@yourip --flake github:your-user/your-repo#your-system
+nix run github:numtide/nixos-remote -- root@yourip --flake github:your-user/your-repo#your-system
 ```
 
 The parameter passed to `--flake` should point to your nixos configuration