remove colophon include because there's only one layout using it now

docs/_includes/colophon.html

-<!-- Footer
-================================================== -->
-<footer class="bs-footer">
-  {% include social-buttons.html %}
-
-  <p>Designed and built with all the love in the world by <a href="http://twitter.com/mdo" target="_blank">@mdo</a> and <a href="http://twitter.com/fat" target="_blank">@fat</a>.</p>
-  <p>Code licensed under <a href="http://www.apache.org/licenses/LICENSE-2.0" target="_blank">Apache License v2.0</a>, documentation under <a href="http://creativecommons.org/licenses/by/3.0/">CC BY 3.0</a>.</p>
-  <ul class="footer-links">
-    <li><a href="http://blog.getbootstrap.com">Blog</a></li>
-    <li class="muted">&middot;</li>
-    <li><a href="https://github.com/twitter/bootstrap/issues?state=open">Issues</a></li>
-    <li class="muted">&middot;</li>
-    <li><a href="https://github.com/twitter/bootstrap/blob/master/CHANGELOG.md">Changelog</a></li>
-  </ul>
-</footer>

docs/_layouts/default.html

@@ -49,8 +49,21 @@
 
     </div>
 
-    <!-- Main docs footer (social buttons, copyright, etc). -->
-    {% include colophon.html %}
+    <!-- Footer
+    ================================================== -->
+    <footer class="bs-footer">
+      {% include social-buttons.html %}
+
+      <p>Designed and built with all the love in the world by <a href="http://twitter.com/mdo" target="_blank">@mdo</a> and <a href="http://twitter.com/fat" target="_blank">@fat</a>.</p>
+      <p>Code licensed under <a href="http://www.apache.org/licenses/LICENSE-2.0" target="_blank">Apache License v2.0</a>, documentation under <a href="http://creativecommons.org/licenses/by/3.0/">CC BY 3.0</a>.</p>
+      <ul class="footer-links">
+        <li><a href="http://blog.getbootstrap.com">Blog</a></li>
+        <li class="muted">&middot;</li>
+        <li><a href="https://github.com/twitter/bootstrap/issues?state=open">Issues</a></li>
+        <li class="muted">&middot;</li>
+        <li><a href="https://github.com/twitter/bootstrap/blob/master/CHANGELOG.md">Changelog</a></li>
+      </ul>
+    </footer>
 
     <!-- JS and analytics only. -->
     {% include footer.html %}