CONTRIBUTING.md

   1 Please see the [official issue tracker], [doc/contributing.rdoc] and wiki [HowToContribute].
   2
   3 [official issue tracker]: https://bugs.ruby-lang.org
   4 [doc/contributing.rdoc]: contributing.rdoc
   5 [HowToContribute]: https://bugs.ruby-lang.org/projects/ruby/wiki/HowToContribute