- add PluginConfig.Background.Styles
- file support, asset management
- opacity, saturation, lightness controls for skybox/image
- coverage controls for image/gradient
- add backgrounds extension with examples
- image handling for build/watch (webpack, cpx)

- moved ts eslint config into overrides

+ build tweaks

- updated all
- removed unused jest-raw-loader
- removed unused circular-dependency-plugin
- removed unused resolve-url-loader

+ fixed lighting demo

- generates sourcemaps that work with vscode/chrome debugging