Merge branch 'patch-2' into 'master'

Fixed a broken documentation link to the wiki-specific-markdown.

## What does this MR do?
Fixes a broken link

## Are there points in the code the reviewer needs to double check?
Well, it's a one line change, so it couldn't hurt, right?

## Why was this MR needed?
Because broken links make us look like chumps. :)

## Screenshots (if relevant)

## Does this MR meet the acceptance criteria?
Probably not.

## What are the relevant issue numbers?
Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/21760.

See merge request !6117

app/views/projects/wikis/_form.html.haml

@@ -24,7 +24,7 @@
 
         = succeed '.' do
           More examples are in the
-          = link_to 'documentation', help_page_path("user/project/markdown", anchor: "wiki-specific-markdown")
+          = link_to 'documentation', help_page_path("user/markdown", anchor: "wiki-specific-markdown")
 
   .form-group
     = f.label :commit_message, class: 'control-label'