Merge pull request #20449 from brson/contributing

Put links to discuss.rust-lang.org and #rust-internals in CONTRIBUTING.m...

Reviewed-by: cmr

Author: bors

CONTRIBUTING.md

@@ -47,5 +47,14 @@ example, if it's 2014, and you change a Rust file that was created in
 // Copyright 2010-2014 The Rust Project Developers.
 ```
 
+# Coordination and communication
+
+Get feedback from other developers on
+[discuss.rust-lang.org][discuss], and
+[#rust-internals][pound-rust-internals].
+
+[pound-rust-internals]: http://chat.mibbit.com/?server=irc.mozilla.org&channel=%23rust-internals
+[discuss]: http://discuss.rust-lang.org
+
 For more details, please refer to
 [Note-development-policy](https://github.com/rust-lang/rust/wiki/Note-development-policy).