fix(variables5) : make shadowing more prominent

closes #375

exercises/variables/variables5.rs

@@ -4,8 +4,8 @@
 // I AM NOT DONE
 
 fn main() {
-    let number = "3"; // don't change this line
-    println!("Number {}", number);
+    let number = "T-H-R-E-E";
+    println!("Spell a Number : {}", number);
     number = 3;
-    println!("Number {}", number);
+    println!("Number plus two is : {}", number + 2);
 }