Web editor documentation needs to be updated

In reflection of the 8.3 update:

http://doc.gitlab.com/ce/workflow/web_editor.html

cc @axil

Reassigned to @axil

Hmm, it's not only 8.3, but also lots of other features prior to 8.3. Thanks.

Milestone changed to 8.5

mentioned in merge request gitlab-com/www-gitlab-com!1045 (merged)

mentioned in merge request !2776 (merged)

Status changed to closed by merge request !2776 (merged)

mentioned in commit e586858e

mentioned in commit ff0ed5f0

mentioned in merge request !14785