fix: change postgis function to returns table

apps/docs/pages/guides/database/extensions/postgis.mdx

@@ -230,7 +230,7 @@ When you are working on a map-based application where the user scrolls through y
 
 ```sql
 create or replace function restaurants_in_view(min_lat float, min_long float, max_lat float, max_long float)
-returns setof record
+returns table (id public.restaurants%TYPE, name public.restaurants%TYPE, location text, dist_meters float)
 language sql
 as $$
 	select id, name, st_astext(location) as location