Remove redundant ports parameters

[krzysztofrewak]

As we discussed earlier, I think this is an overkill:

bash <(curl -s https://raw.githubusercontent.com/blumilksoftware/boilerplate/init.sh) <app-name> [app-namespace] [branch-name] [app-host-port] [db-host-port] [mailpit-dashboard-port] [redis-host-port]

I would prefer to provide only app-host-port and then next ports would be by default set up to app-host-port + 1, app-host-port + 2 and so on. Current solution should stay if anyone would like to set up some specific ports as well.

Btw. hosts are changed in .env.example, but not in docker-compose.yml and readme.md. It should be changed there as well.