Add award emoji docs

[ci skip]

doc/intro/README.md

@@ -14,7 +14,7 @@ Create issues, labels, milestones, cast your vote, and review issues.
 - [Create a new issue](../gitlab-basics/create-issue.md)
 - [Assign labels to issues](../workflow/labels.md)
 - [Use milestones as an overview of your project's tracker](../workflow/milestones.md)
-- Use voting to express your like/dislike to the issue in demand
+- [Use voting to express your like/dislike to the issue in demand](../workflow/award_emoji.md)
 
 ## Collaborate
 

doc/workflow/award_emoji.md

+# Award emojis
+
+>**Note:**
+This feature was [introduced][1825] in GitLab 8.2.
+
+As a remote worker, you get fewer opportunities for high-fives and thumbs-ups.
+In order to make virtual celebrations easier, you can now vote on issues and
+merge requests using emoji!
+
+![Award emoji](img/award_emoji_select.png)
+
+This makes it much easier to give and receive feedback, without a long comment
+thread. Any comment that contains only the thumbs up or down emojis is
+converted to a vote and depicted in the emoji area.
+
+You can then use that functionality to sort issues and merge requests based on
+popularity.
+
+## Sort issues and merge requests on vote count
+
+>**Note:**
+This feature was [introduced][2871] in GitLab 8.5.
+
+You can quickly sort the issues or merge requests by the number of votes they
+have received. The sort option can be found in the right dropdown menu.
+
+![Votes sort options](img/award_emoji_votes_sort_options.png)
+
+---
+
+Sort by most popular issues/merge requests.
+
+![Votes sort by most popular](img/award_emoji_votes_most_popular.png)
+
+---
+
+Sort by least popular issues/merge requests.
+
+![Votes sort by least popular](img/award_emoji_votes_least_popular.png)
+
+---
+
+The number of upvotes and downvotes is not summed up. That means that an issue
+with 18 upvotes and 5 downvotes is considered most popular than an issue with
+17 upvotes and no downvotes.
+
+[2871]: https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/2781
+[1825]: https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/1825