Read only postgres user.txt

Read only postgres user

```sql
CREATE ROLE read_only;

GRANT USAGE ON SCHEMA public TO read_only;
GRANT SELECT ON ALL TABLES IN SCHEMA public TO read_only;
GRANT USAGE, SELECT ON ALL SEQUENCES IN SCHEMA public TO read_only;

ALTER DEFAULT PRIVILEGES IN SCHEMA public GRANT SELECT ON TABLES TO read_only;

CREATE USER reader WITH PASSWORD 'hunter2';
GRANT read_only TO reader;
```