## Sample Code Documentation

This document demonstrates multiple code blocks with different languages.

### Rust Example

```rust
fn main() {
    println!("Hello, world!");
}
```

### Python Example

```python
def greet(name):
    print(f"Hello, {name}!")
```

### JavaScript Example

```javascript
function add(a, b) {
    return a + b;
}
```

## Conclusion

These examples show basic syntax in different programming languages.