Cool! I can't promise any contributions, but I hope it succeeds. 2 things: it looks like this is a platform for generalized build/tech trees, and I think that is the right approach. I think you need a "poster child" project though, like what Wikipedia is to Mediawiki. Pick something that everyone can benefit from, for example the "civilization build tree". And start drawing attention to it, which will draw attention to engine powering it.

Imo, the biggest area to focus will be reducing the barrier to entry. We're people who are comfortable with version control, but your average person isn't. The underlying software can still be version controlled, but you need a way for normal people to add/edit/remove nodes so that they can start contributing. You also need a system for inferring experts in different areas, and allowing them elevated privileges.