GitHub Issues Workflow for Chef

This RFC codifies the workflow of Chef maintainers while maintaining issues and contributions for Chef.

Special thanks to @btm / @lamont-granquist / @danielsdeleo / @mcquin / @adamedx / @jdmundrawala  who has helped put the first version come together.
By "Issues" I'm referring to all of bugs / feature requests / style decisions. IMO they shouldn't have different workflows.

In order to keep the complexity down, we didn't cover the obvious cases where an issue is not applicable, being closed as won't fix, moving to RFC etc... 

If there is no resolution, Issue will keep up showing up in "things to review" list.