Zero configuration support

This package should support the scenerio when the project doesn't include any `webpack.config`, it should automatically generate a configuration file for webpack in order to support zero-configuration like Meteor aims.

Start by examining how webpack.config is currently discovered and used, then determine the expected behavior when a project has no configuration file. Define the generated configuration and verify zero-configuration behavior in a project without webpack.config; the issue does not name tests or an entry point.

Written by the indexing model from the issue text.