Restored change to extended storage

sql/vector--0.3.2--0.4.0.sql

@@ -1,6 +1,9 @@
 -- complain if script is sourced in psql, rather than via CREATE EXTENSION
 \echo Use "ALTER EXTENSION vector UPDATE TO '0.4.0'" to load this file. \quit
 
+-- requires Postgres 13+
+-- ALTER TYPE vector SET (STORAGE = extended);
+
 CREATE FUNCTION vector_accum(double precision[], vector) RETURNS double precision[]
 	AS 'MODULE_PATHNAME' LANGUAGE C IMMUTABLE STRICT PARALLEL SAFE;