discourse/discourse — pull request #895 by GlitchMr (2013-05-24 14:34:39+00:00)
Title: Use relative URLs, not absolute.

This helps if somebody would fork a GitHub repository, as the links
now lead to files in fork, not files in original repository. Also, it
makes more sense when reading Markdown files locally.

https://github.com/blog/1395-relative-links-in-markup-files