Bevy UI theming

When to use

Load this when many nodes should share colors or a widget style. There is no Godot Theme resource in Bevy.

ECS shape

• Per-node colors opened: BackgroundColor, BorderColor, BorderRadius, BoxShadow, BackgroundGradient.
• Feature: bevy_feathers is a collection of styled widgets for editors and inspectors. Check that module for widget names before writing them.
• Window chrome: WindowTheme is an enum on bevy::window for the window theme variant. That is OS window chrome, not a UI skin.
• Systems: you set components. No theme inheritance system was named.

Coming from Godot