docs(own-and-return): make usage example clearer

subjects/own-and-return/README.md

@@ -38,9 +38,12 @@ pub struct Film {
 }
 
 fn main() {
-    let my_film = Film { name: "Terminator" };
-    println!("{}",  take_film_name(/* to be implemented */);
-    println!("{}",  read_film_name(/* to be implemented */);
+    let my_film = Film { name: "Terminator".toString() };
+    println!("{}", take_film_name(/* to be implemented */));
+    // the order of the print statements is intentional, if your implementation is correct, you should have a compile error because my_film was consumed
+    println!("{}", read_film_name(/* to be implemented */));
+    println!("{}", take_film_name(/*to be implemented*/))
+    // you can test this function by commenting out the first print statement, you should see the expected output without errors in this case
 }
 ```
 
@@ -50,6 +53,5 @@ And its output:
 $ cargo run
 Terminator
 Terminator
-Terminator
 $
 ```