I don't really have a strong argument against it (despite the habbit of temporary solutions to become permanent
). Just wanted to say that I never liked this anywhere I encountered it, cause I tend to think "cool, it's all documented, so I can start right with feature XXX", but have to find out that there is just "coming soon" or "under construction" once I ran into problems and digged deeper.
I rather vote for a small clean documentation than a big one where a lot of chapters are just placeholders.
But again, that's maybe just me, I really don't want to talk you out of this... just my 2 cents.