Reference non-goals in contributing guidelines
@@ -11,7 +11,7 @@ Prometheus uses GitHub to manage reviews of pull requests.
* If you plan to do something more involved, first discuss your ideas
on our [mailing list](https://groups.google.com/forum/?fromgroups#!forum/prometheus-developers).
This will avoid unnecessary work and surely give you and us a good deal
- of inspiration.
+ of inspiration. Also please see our [non-goals issue](https://github.com/prometheus/docs/issues/149) on areas that the Prometheus community doesn't plan to work on.
* Relevant coding style guidelines are the [Go Code Review
Comments](https://code.google.com/p/go-wiki/wiki/CodeReviewComments)
