This PR fix two things:

• %kernel.public_dir% does not exists and%kernel.project_dir%/public is the correct path.
• As mentioned hereproblem with Multiple Webpack Configurations webpack-encore#477, the multiple config will overwrite theentrypoint.js. The solution is to use two build directories, but this needs two different paths in thewebpack.config.js.

Now someone can just copy&paste the code lines and it should work.