readme: add password parameter when connect to PostgreSQL (#299)

README.md

@@ -67,7 +67,7 @@ Examples:
     goose sqlite3 ./foo.db create fetch_user_data go
     goose sqlite3 ./foo.db up
 
-    goose postgres "user=postgres dbname=postgres sslmode=disable" status
+    goose postgres "user=postgres password=postgres dbname=postgres sslmode=disable" status
     goose mysql "user:password@/dbname?parseTime=true" status
     goose redshift "postgres://user:[email protected]:5439/db" status
     goose tidb "user:password@/dbname?parseTime=true" status