Add nix subsection to "installation"

README.md

@@ -102,9 +102,17 @@ Hevi has a precedence for configuration and it is:
 It is written in [zig](https://github.com/ziglang/zig), in an attempt to simplify hex viewers.
 
 ## Installation
+
 ### Some Linux package managers
 If your package manager is in the following list (and preferably in green), you can simply install it from there:
 [![Packaging status](https://repology.org/badge/vertical-allrepos/hevi.svg)](https://repology.org/project/hevi/versions)
+
+### Nix
+There is a nix flake you can use. You can also try hevi without installing it:
+```
+$ nix shell github:Arnau478/hevi
+```
+
 ### Other platforms
 You can download a binary from the [releases](https://github.com/Arnau478/hevi/releases/) page. You can also clone the repository and compile it with `zig build`.