update useLandmark docs category and aria-label (#5509)

Author: reidbarber

packages/@react-aria/landmark/docs/useLandmark.mdx

@@ -16,7 +16,7 @@ import {Keyboard} from '@react-spectrum/text';
 import packageData from '@react-aria/landmark/package.json';
 
 ---
-category: Utilities
+category: Interactions
 keywords: [landmarks, aria]
 ---
 
@@ -103,7 +103,7 @@ function Search(props) {
     </ul>
   </Navigation>
   <Search />
-  <Region>
+  <Region aria-label="Example region">
     <h2>Region</h2>
     <p>Example region with no focusable children.</p>
   </Region>