fix: move_semantics5 hints

Improve the hints for move_semantics5, as well as the explanatory
comments in the code.

Previously, it was not clear what possible changes were allowed.
It seems that reordering the statements might be the intended solution.
The previous comment about not "adding newlines" doesn't make sense,
so treating it as "adding new lines" makes it more clear.

Author: tlyu

exercises/move_semantics/move_semantics5.rs

@@ -1,5 +1,6 @@
 // move_semantics5.rs
-// Make me compile without adding any newlines or removing any of the lines.
+// Make me compile without adding, removing, or changing any of the
+// lines in `main()`.
 // Execute `rustlings hint move_semantics5` for hints :)
 
 // I AM NOT DONE

info.toml

@@ -216,10 +216,14 @@ path = "exercises/move_semantics/move_semantics5.rs"
 mode = "compile"
 hint = """
 Carefully reason about the range in which each mutable reference is in
-vogue. Does updating the value of referent (x) immediately after the
-mutable reference is taken helps? Read more about 'Mutable References'
+vogue. Does it help to update the value of referent (x) immediately after
+the mutable reference is taken? Read more about 'Mutable References'
 in the book's section References and Borrowing':
-https://doc.rust-lang.org/book/ch04-02-references-and-borrowing.html#mutable-references."""
+https://doc.rust-lang.org/book/ch04-02-references-and-borrowing.html#mutable-references.
+
+Additional hint:
+If you can't add, change, or remove any statements in `main()`, can you
+reorder them in a way that lets the program compile?"""
 
 # PRIMITIVE TYPES