fix layout reference docs

docs/router/src/reference/layouts.md

@@ -1,8 +1,8 @@
 # Layouts
 
-Layouts allow you to 
+Layouts allow you to wrap all child routes in a component. This can be useful when creating something like a header that will be used in many different routes.
 
-[`Outlet`]s tell the router where to render content in layouts. In the following example,
+[`Outlet`] tells the router where to render content in layouts. In the following example,
 the Index will be rendered within the [`Outlet`].
 
 ```rust, no_run