feat(docs): update sidebar to categorize Usecases and clean up usecases.md

Author: phodal

docs/usecases/usecases.md

@@ -1,8 +1,6 @@
 ---
 layout: default
 title: Use Cases
-nav_order: 999
-has_children: false
 ---
 
 TODO: Usecases

sidebars.js

@@ -133,12 +133,12 @@ const sidebars = {
 		},
 		'troubleshooting',
 		{
-			type: 'usecases',
+			type: 'category',
 			label: 'Usecases',
 			items: [
 				'usecases/usecases'
 			],
-		}
+		},
 	],
 }