feat(services): add preliminary postgresql config

Changed files
+10
systems
koumakan
services
+10
systems/koumakan/services/postgresql.nix
···
+
{ pkgs, ... }:
+
+
{
+
services.postgresql = {
+
enable = true;
+
+
package = pkgs.postgresql_15;
+
dataDir = "/var/lib/postgresql/15";
+
};
+
}