add sql script to remove old entries from feeds

vacuum.sql

@@ -0,0 +1,10 @@
+DELETE FROM entry
+USING (
+  SELECT
+    id,
+    retrieved,
+    ROW_NUMBER() OVER (PARTITION BY feed_id ORDER BY retrieved DESC) AS row
+  FROM entry
+) AS numbered
+WHERE entry.id = numbered.id
+  AND (numbered.row > 2000 OR numbered.retrieved < CURRENT_DATE - INTERVAL '365 days')