Replace copy configuration with automatic copying via Webpack

As mentioned in #33, the current way how copying assets (fonts, images) work is by manually configuring paths for a copy task. This works a bit against the concept of Webpack, which should automatically resolve dependencies and then copy them.

I can provide these changes via a pull request, as I already updated this behavior in my projects which are using patternlab-edition-node-webpack. So it's tested in multiple production projects.

Start by tracing the current manually configured copy task for fonts and images and read the related discussion in issue #33. Compare the existing asset flow with Webpack dependency resolution, then verify that required supporting assets are copied without manual paths.

Do mô hình lập chỉ mục viết ra từ nội dung của issue.