chore: add an example for using double array in postgres

psql-tags/tables.sql

@@ -8,6 +8,7 @@ CREATE TABLE IF NOT EXISTS tags (
 CREATE TABLE IF NOT EXISTS rooms (
     id varchar PRIMARY KEY,
     tag_ids varchar[] DEFAULT '{}' ::varchar[] NOT NULL,
+    coordinates double precision[] NOT NULL,
     created_at timestamp NOT NULL DEFAULT now(),
     updated_at timestamp NOT NULL DEFAULT now()
 );