Update tutorial.rst (#6766)

Just spicing it up a bit.

docs/getting_started/tutorial.rst

@@ -2,7 +2,7 @@ Your first Wagtail site
 =======================
 
 .. note::
-   This tutorial covers setting up a brand new Wagtail project.
+   This tutorial covers setting up a brand new Wagtail project!
    If you'd like to add Wagtail to an existing Django project instead, see :doc:`integrating_into_django`.
 
 Install and run Wagtail