chore(neon): Fix missing @endtemplate

Signed-off-by: jld3103 <jld3103yt@gmail.com>

packages/neon/neon/lib/src/widgets/adaptive_widgets/list_tile.dart

@@ -41,6 +41,7 @@ class AdaptiveListTile extends StatelessWidget {
   /// {@template neon.AdaptiveListTile.subtitle}
   /// A [subtitle] is used to display additional information. It is located
   /// below [title]. Usually a [Text] widget.
+  /// {@endtemplate}
   final Widget? subtitle;
 
   /// {@template neon.AdaptiveListTile.additionalInfo}