The documentation README was previously intended to be read from
the documentation repository, not from the source repository.
This had the potential to give off the impression that documentation
pull requests were not allowed, when exactly the opposite is the
case. The README has been improved to make it more clear how to
contribute pull requests to update the documentation.
Thanks to Brent Connor [1] for pointing out this issue over at
Stack Overflow [2].
[1]: https://stackoverflow.com/users/3954106/brent-connor
[2]: http://stackoverflow.com/q/28705192/359284