Update server utilities index

Author: jspahrsummers

docs/specification/server/utilities/_index.md

@@ -5,3 +5,11 @@ title: Utilities
 {{< callout type="info" >}}
 **Protocol Revision**: {{< param protocolRevision >}}
 {{< /callout >}}
+
+These optional features can be used to enhance server functionality.
+
+{{< cards >}}
+  {{< card link="completion" title="Completion" icon="at-symbol" >}}
+  {{< card link="logging" title="Logging" icon="terminal" >}}
+  {{< card link="pagination" title="Pagination" icon="collection" >}}
+{{< /cards >}}