Direct contributors to the issue tracker

Author: lambda-fairy

README.md

@@ -67,4 +67,7 @@ You should start with [the template](template.md). Copy it into the appropriate
 directory, edit it, and submit a PR. You might not want every section, and you
 might want to add extra sections.
 
+We suggest leaving a comment on the [issue tracker](https://github.com/rust-unofficial/patterns/issues)
+so that other people don't start working on the same topic.
+
 Correction and elaboration PRs are very welcome.