Remove "git from the bottom up" because the site is 404

Author: ryansb

_layouts/default.html

@@ -57,7 +57,6 @@ <h3 id="blue">resources</h3>
       <a href="http://progit.org/">Pro Git Book</a>
       <a href="http://gitref.org/">Git Reference</a>
       <a href="http://cworth.org/hgbook-git/tour/">A tour of git: the basics</a>
-      <a href="http://www.newartisans.com/2008/04/git-from-the-bottom-up.html">Git from the bottom up</a>
       <a href="http://gitimmersion.com/">Git Immersion</a>
       <a href="http://www.gitguys.com/">Git Guys</a>
     </div>