Document nixpkgs package

Author: vimpostor

README.md

@@ -9,7 +9,7 @@ https://github.com/vimpostor/blobdrop/assets/21310755/1957b6a7-475c-4930-80b9-18
 
 # Installation
 
-Note: For Arch Linux users there is an [AUR package](https://aur.archlinux.org/packages/blobdrop-git), for Nix users there is a [flake](flake.nix) available.
+Note: For Arch Linux users there is an [AUR package](https://aur.archlinux.org/packages/blobdrop-git), for Nix users there is a [flake](flake.nix) available and an official package in [nixpkgs](https://github.com/NixOS/nixpkgs/blob/master/pkgs/by-name/bl/blobdrop/package.nix).
 You can also download an AppImage from the [latest release](https://github.com/vimpostor/blobdrop/releases/latest).
 
 ## Building from source