docs: add zig installation instructions to installation prerequisites (#85)

Author: flavioescobar

pages/installation.md

@@ -28,6 +28,8 @@ First, Install git LFS by [following these instructions](https://docs.github.com
 
 Next, [install `just`](https://github.com/casey/just?tab=readme-ov-file#cross-platform)
 
+Next, [install `zig`](https://ziglang.org/learn/getting-started/) if not already installed. **Important:** version 0.14.1 is required, which is currently _not_ the latest version.
+
 Then, clone the git repository. Do this with
 
 ```elixir