Added sise into Networking

[aytchell]

sise is a simple to use SSDP client (Simple Service Discovery Protocol; which is the "service discovery" part of UPnP)

The implementation is compatible with the UPnP 2.0 spec. Users of the application can either manually get(...) the found services and devices or subscribe(...) to be notified.

Documentation: https://hexdocs.pm/sise/Sise.html Hex: https://hex.pm/packages/sise Github: https://github.com/aytchell/sise