website: add Free Electrons as a current sponsor

Free Electrons sponsored the Buildroot Developers Meeting at ELCE 2016
in Berlin by making a donation to IN-Berlin, the organization who hosted
the 3-day event.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

docs/website/sponsors.html

@@ -26,6 +26,23 @@
 	  </div>
 	</div>
 
+	<div class="col-sm-12">
+	  <div class="panel panel-default">
+	    <div class="panel-body">
+	      <div class="col-sm-4">
+		<a href="http://www.free-electrons.com">
+		  <img class="img-responsive center-block" src="images/free-electrons-logo.png"/>
+		</a>
+	      </div>
+	      <div class="col-sm-8">
+		<a href="http://www.free-electrons.com">Free
+		Electrons</a> is sponsoring the <a href="http://elinux.org/Buildroot:DeveloperDaysELCE2016">Buildroot
+		Developers Meeting at ELCE 2016</a> in Berlin, by making a donation to the
+		<a href="http://in-berlin.de/">IN-Berlin</a> organization who hosted the event.
+	      </div>
+	    </div>
+	  </div>
+
     </div>
   </div>