Docs: Breaks out Utilities into separate section and optimizes its pages (#20678)

docs/_data/nav.yml

@@ -53,6 +53,20 @@
     - title: Tooltips
     - title: Utilities
 
+- title: Utilities
+  pages:
+    - title: Clearfix
+    - title: Close icon
+    - title: Colors
+    - title: Display property
+    - title: Image replacement
+    - title: Invisible content
+    - title: Responsive helpers
+    - title: Screenreaders
+    - title: Sizing and positioning
+    - title: Spacing
+    - title: Typography
+
 # - title: Extend
 #   pages:
 #     - title: Approach