I haven't actually tested this but if you take a look at file inc.markdown.php you'll find 4 instances of the text <a href= that are not in comments.
You could try turning them into <a target="_blank" href= and see if that gives you the results you want.
Welcome to the Q&A site for Question2Answer.
If you have a question about Q2A, please ask here, in English.
To report a bug, please create a new issue on Github or ask a question here with the bug tag.
If you just want to try Q2A, please use the demo site.