The `description.xml` file is part of the UPnP Service Discovery protocol, see https://docs.microsoft.com/en-us/openspecs/windows_protocols/ms-rxad/9225d145-6b2c-40d5-8ee8-7d837379fc25
Move the UPnP/SSDP Manager autodiscovery code into from `main.go` into the `worker` package. This also means changing the error handling a bit, as only the `main.go` file is allowed to do `log.Fatal()`.