diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index f7702a42..5a470121 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -108,8 +108,9 @@ And compiles to:
 echo "Hello World"
 ```
 
+<details>
+<summary>Let's start!</summary>
 Let's create a `src/modules/builtin/builtin.rs` file with the following content:
-
 ```rs
 // This is the prelude that imports all necessary stuff of Heraclitus framework for parsing the syntax
 use heraclitus_compiler::prelude::*;
@@ -199,6 +200,7 @@ impl Statement {
     // ...
 }
 ```
+</details>
 
 ### 3. Runtime libraries
 #### 3.1. `stdlib`