Attachments docs: Point to uses in example

Author: simolus3

demos/supabase-todolist/lib/attachments/queue.dart

@@ -53,12 +53,3 @@ Future<Attachment> savePhotoAttachment(
     },
   );
 }
-
-Future<Attachment> deletePhotoAttachment(String fileId) async {
-  return await attachmentQueue.deleteFile(
-    attachmentId: fileId,
-    updateHook: (context, attachment) async {
-      // Optionally update relationships in the same transaction
-    },
-  );
-}

packages/powersync_core/doc/attachments.md

@@ -33,6 +33,11 @@ The attachments' state is stored in a local-only attachments table.
 
 See the [supabase-todolist](https://github.com/powersync-ja/powersync.dart/tree/main/demos/supabase-todolist) demo for a basic example of attachment syncing.
 
+In particular, relevant snippets from that example are:
+
+- The attachment queue is set up [here](https://github.com/powersync-ja/powersync.dart/blob/98d73e2f157a697786373fef755576505abc74a5/demos/supabase-todolist/lib/attachments/queue.dart#L16-L36), using conditional imports to store attachments in the file system on native platforms and in-memory for web.
+- When a new attachment is added, `saveFile` is called [here](https://github.com/powersync-ja/powersync.dart/blob/98d73e2f157a697786373fef755576505abc74a5/demos/supabase-todolist/lib/attachments/queue.dart#L38-L55) and automatically updates references in the main schema to reference the attachment.
+
 ### Setup
 
 First, add a table storing local attachment state to your database schema.