feat: couple more lessons

src/functions.rs

@@ -0,0 +1,17 @@
+fn fizzbuzz(n: i32) {
+    for i in 1..=n {
+        if i % 15 == 0 {
+            println!("FizzBuzz");
+        } else if i % 5 == 0 {
+            println!("Buzz");
+        } else if i % 3 == 0 {
+            println!("Fizz");
+        } else {
+            println!("{i}");
+        }
+    }
+}
+
+pub fn functions_module() {
+    fizzbuzz(10);
+}