Build script doesn't copy asset folders from src/example/folder to dist

[vorg]

Eg https://github.com/vorg/pex-examples/tree/master/src/materials.All.spaceTransformations has materials and shaders folder that are not copied to dist/ on build

src

materials.All.spaceTransformations
├── main.js
├── materials
└── shaders

dist

materials.All.spaceTransformations
├── main.min.js
├── index.html
├── thumb.jpg
├── materials //missing
└── shaders //missing