fix the language of Cargo calls

should be a shell, not TOML

Author: amtoine

blog/2024-04-30-nushell_0_93_0.md

@@ -101,7 +101,7 @@ in the rest of this section, we will build a very simple Rust binary application
 new `nuon` crate works :)
 
 first, let's define some dependencies
-```toml
+```nushell
 cargo add clap --features derive
 cargo add nuon
 ```