I am working on fifthtry.com to solve exactly this problem. We organise stuff in tree. Eg you can see my person blog hosted on it: www.fifthtry.com/amitu/. We

I am working on fifthtry.com to solve exactly this problem. We organise stuff in tree. Eg you can see my person blog hosted on it: www.fifthtry.com/amitu/. We are working integrating with diagram tools. Regarding sync: we connect with github and block pull request till it is documented and approved on fifthtry. Would love to demo it to you if interested, email in my profile.