the docs appear to have this corrected at https://github.com/JuliaLang/julia/blob/735847010c84ad6b54ff675d713346ffe8981d07/doc/manual/parallel-computing.rst
but, it does not appear to be the case that this flows through to the front-page matter at http://julialang.org in particular, a GitSearch of the julialang repository for the string "nheads" has one result, see link above.
