如何导入现有节点。js模块变成Intellij IDEA?

I have an existing Node.js codebase, forked from GitHub. Now I want to import it to the Intellij IDEA 13 (ultimate version, which supports Node.js). When I simply try to import the project from the root folder of my existing code, IDEA doesn't add the 'lib' folder, where all the sources are. It should be simple, but I cannot figure it out. Any hints?I have an existing Node.js codebase, forked fro