Markdown docs' Inline Diff examples are incomplete

Problem to solve

On the MarkDown documentation page, under the Inline Diff section, the example doesn't display what the entered markdown text should show.

Further details

This is the section that needs fixing: https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/user/markdown.md#inline-diff

Who can address the issue

Anyone who knows how the markdown works or how it is rendered on the page.