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.
They were looking kind of floaty, moving not like spaceships but like
they were on ice. Now they travel along their orientation, towards
where the player is/will be.
The use of `not is_inside_tree()` before setting the setting class' value
meant that the starting values would always be the default. Moving the
value setting before checking for tree readiness fixes the issue.
Used `var variable := 0.0` as discussed in the Godot issue, instead of
`var variable: = 0.0`.
Mostly these are minor/cosmetic changes, but I've also reorganized the
folder structure (naming of folders) to reflect our guidelines, plus
made some minor changes to the demo codes. Still work in progress.
