de-conflict linking

on github the link was getting made into html like this:

"""
<a href="http://eukaryota.dathub.org" target="_blank"></a><a href="http://eukaryota.dathub.org">http://eukaryota.dathub.org</a>
"""

which is clearly wrong; over-eager markdown conversion (maybe specific to github-flavored).

Also, on the get-dat adventure, the link just doesn't work at all; you can't click it. I'm not sure why that is though.