added milestone information

CONTRIBUTING.md

@@ -46,7 +46,6 @@ For the subject of an issue, please start it by writing the feature or functiona
   - **High**: it’s a priority to be completed for the assigned milestone
   - **Medium**: planned for that milestone, but if needed, it can be re-considered
 - **Status**:
-  - **In Design**: mockups and wireframes are being created
   - **In Dev**: being developed
   - **In QA**: testing to make sure it is behaving as wanted
 - **Type**:
@@ -60,6 +59,11 @@ You can attach an image or screenshot by dragging and dropping, selecting them,
 
 [supported image format]: https://help.github.com/articles/issue-attachments
 
+## Milestones
+  - **In Review**: milestone for issues that are being reviewed for future releases
+  - **In Design**: milestone for issues that are being designed (FRDs, mockups, technical specifications, etc happen during this milestone). This is a way to see what we are working on for future releases
+  - **Candidate** candidate for [version]" means that it is only under consideration. A developer worka on issues that have been tagged with a particular milestone before dipping into the corresponding "candidate for" milestone. Usually are "nice to have" features or bug fixes for a release if there is time left after the primary work is done.
+
 ## Documentation
 
 The source for the documentation at http://guides.dataverse.org is in the GitHub repo under the "[doc][]" folder. If you find a typo or inaccuracy or something to clarify, please send us a pull request!