I do not think you will find these yet, as JFD[C] is not yet released. What is released if JFE and JFP[E]. Docs are not generally provided until product/SW is released. If you are interested in this technology, suggest you contact either your local Juniper Account team or Partner. In the meanwhile, I would also suggest you look at JFE docs, as JFD[C] is very similar with exception that JFD[C] provides for local switching support, but does not support concept of a edge 'cluster'.
Hope this helps.