Based on the 2D Beginner Project look, these demos now have the colorful
GDQuest "theme" to them.
This had the effect of removing the circle and triangle/ship sprites as
everything is drawn in Godot directly.
Add quickstart guide and quickstart demo
Authored by Razoric and edited by Nathan and Johnny.
The purpose of the guide is simply to give an overview of what the
behaviors are there for, and a quick look at how to actually make use
of them in the basis of this toolkit, with some explanatory comments.
The actual user's manual will be built out of the API reference.
