Put interactive book notice in a blockquote box to draw attention to it

src/title-page.md

@@ -21,6 +21,6 @@ Press][nsprust].
 [nsprust]: https://nostarch.com/rust
 [translations]: appendix-06-translation.html
 
-**🚨 Want a more interactive learning experience? Try out a different version
-of the Rust Book, featuring: quizzes, highlighting, visualizations, and more**:
-<https://rust-book.cs.brown.edu>
+> **🚨 Want a more interactive learning experience? Try out a different version
+> of the Rust Book, featuring: quizzes, highlighting, visualizations, and
+> more**: <https://rust-book.cs.brown.edu>