Merge branch 'master' into refactor-hints

exercises/functions/functions5.rs

@@ -1,6 +1,8 @@
 // functions5.rs
 // Make me compile! Execute `rustlings hint functions5` for hints :)
 
+// I AM NOT DONE
+
 fn main() {
     let answer = square(3);
     println!("The answer is {}", answer);