feat: add hello-world example for using rust

hello-world/Cargo.toml

@@ -0,0 +1,8 @@
+[package]
+name = "hello-world"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]

hello-world/src/main.rs

@@ -0,0 +1,67 @@
+use std::fmt;
+
+#[derive(Debug)]
+struct Person<T: AsRef<str>> {
+    name: T,
+    age: u8,
+}
+
+// T is the inner type of the Person to store the name, here
+// we want it to have an implementation for display.
+impl<T: AsRef<str> + fmt::Display> fmt::Display for Person<T> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        return write!(
+            f,
+            "There is a person with name: {} and age {}",
+            self.name, self.age
+        );
+    }
+}
+
+fn main() {
+    println!("Hello, world!, because it is a hello world example");
+
+    let _h: &str = "Hello";
+
+    // create a person using an AsRef
+    let mut p = Person {
+        name: "Parham Alvani",
+        age: 25,
+    };
+
+    println!("{}", p);
+
+    {
+        let name: String = String::from("Elahe Dastan");
+        p.name = name.as_str();
+
+        println!("{}", p);
+    }
+
+    // uncomment the following line to get a nice compile error
+    // because it __moves__ into inner context and name doesn't live
+    // enough
+    // println!("{}", p);
+
+    let mut p = Person {
+        name: String::from("Raha Dastan"),
+        age: 23,
+    };
+
+    p.name.push('!');
+
+    println!("{}", p);
+
+    // learn about clourses
+    let p = Person {
+        name: "Parham Alvani",
+        age: 25,
+    };
+
+    let parham_namer = || {
+        println!("{}", p.name);
+    };
+
+    parham_namer();
+    parham_namer();
+}