Add init commands to execute as postgres user (admin) to docu about ltss HOT 1 OPEN

@FireEmerald
Thanks for opening this issue, you bring up an interesting point here and I think I agree with you.

Currently, there is some logic in the component setup that revolves around the availability of timescaledb and postgis extensions (i.e. NOT that they are actually installed, only that they are available for installation) to support LTSS on vanilla postgres and with timescaledb and/or postgis extensions available (see #29 for details).

Maybe this logic should be changed to check for installed extensions rather than available extensions such that the user runs none/any/all of the below during the initial setup and thus also configures LTSS implicitly.

CREATE EXTENSION IF NOT EXISTS postgis CASCADE;
CREATE EXTENSION IF NOT EXISTS timescaledb CASCADE;

Do you have any further input/opinions?

from ltss.