If you'd like to help make Ruby's documentation better, it's actually
really easy!

http://blog.steveklabnik.com/2011/05/10/contributing-to-ruby-s-documentation.html

We're actually undergoing a documentation drive to chip in and help
make 1.9.3's documentation the best yet, and I'm sure that better
documentation for Readline would get merged in if you'd contribute
some.