refer to the contributing guide on how to create issues.

Our contribution guide has a section on how to create issues. The CONTRIBUTING.md proxy currently only states to read the guide if you want to write code.

I created a link to the reporting section for people that only want to report a bug. I also formatted the different points in a list.

You can view the final file here: https://github.com/senny/rails/blob/how_to_report_an_issue/CONTRIBUTING.md