update schema for new price feed subscription migration

db/schema.sql

@@ -46,7 +46,8 @@ CREATE FUNCTION public.notify_pricefeed() RETURNS trigger
 BEGIN
   PERFORM pg_notify(
     CAST('postgraphile:price_feed' AS text),
-    row_to_json(NEW)::text);
+    json_build_object('__node__', json_build_array('price_feeds', NEW.id))::text
+  );
   RETURN NEW;
 END;
 $$;