Some users connect PostgREST to the wrong PostgreSQL instance - likely because they are
not even aware that another instance is running. By using the standard port 5432 instead
of 5433, we avoid this problem. The user will be made aware very early that they have
another postgresql instance running - and can solve the problem at this stage. If they
decide to change the port, they are much more likely to remember that in the later stages
of the tutorial, too.
Resolves https://github.com/PostgREST/postgrest-docs/issues/304
