Improve cleanup-crew.md with an example post

Add a post which explains how to use C-reduce with Rust in cleanup-crew.md

src/notification-groups/cleanup-crew.md

@@ -41,7 +41,7 @@ are a few:
   code automatically.
   * The [C-reduce](https://github.com/csmith-project/creduce) tool also works
     on Rust code, though it requires that you start from a single
-    file. (XXX link to some post explaining how to do it?)
+    file. (A post explaining how to do it can be found [here](https://insaneinside.net/2017/09/12/whole-crate-bug-reduction-with-creduce.html).)
 * pnkfelix's [Rust Bug Minimization Patterns] blog post
   * This post focuses on "heavy bore" techniques, where you are
     starting with a large, complex cargo project that you wish to