godot_xbox version 1.0

This release adds the ability to use Leaderboards, changes the previous "SignIn" class to "Xbox" since it is no longer used for only signing in, and has a few quality of life improvements. Check documentation/readme for info on how to get started.

godot_xbox version 0.1

This is a rough implementation and is not fully tested and working. This has been tested in development environments and works on PC, but fails on xbox. Further work will be needed to make this work on xbox.