How to Add a Greeting Method to the Human Structure

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# How to Add a Greeting Method to the Human Structure

What the reader will be able to do: Define a method on the `Human` struct that prints a personalized greeting.

## Prerequisites
- Basic understanding of Rust structs and mutability (from previous tutorials)
- Familiarity with `fn main()` and `println!`

## Steps

1. **Define the `Human` struct**  
   Open `src/main.rs` and ensure you have:
   ```rust
   struct Human {
       name: String,
       age: u32,
   }
   ```

2. **Add a method to the `Human` struct**  
   Replace the `main()` function with:
   ```rust
   impl Human {
       fn greet(&self) {
           println!("Hello, my name is {} and I am {} years old.", self.name, self.age);
       }
   }

   fn main() {
       let person = Human {
           name: String::from("Alice"),
           age: 30,
       };

       person.greet();
   }
   ```

3. **Compile and run**  
   Run:
   ```bash
   cargo run
   ```
   Expected output:
   ```
   Hello, my name is Alice and I am 30 years old.
   ```

## Pitfalls
- Forgetting to use `self` in the method definition
- Using `&mut self` instead of `&self` when the method doesn't modify the struct
- Not implementing the `impl` block correctly (missing `fn` keyword)

## To Go Further
- Learn how to implement multiple methods on the same struct
- Explore how to use `self` in different ways (`&self`, `&mut self`, `self`)
- Study how to return values from methods instead of printing them