fix: update API index page title and navigation structure

Author: schamane

docs/_api/index.html

@@ -1,9 +1,8 @@
 ---
-title: "API Reference"
+title: "Index"
 layout: api
-parent: Documentation
-nav_order: 4
-has_children: true
+parent: API Reference
+nav_order: auto
 ---
 
 <div class="col-content"><div class="tsd-page-title"><h1>node-syslog API</h1>