website/news: update with release date and announcement e-mail link

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

docs/website/news.html

@@ -8,12 +8,14 @@
 <p>
 
 <ul>
-  <li><b>xxx November 2015 -- 2015.11-rc1 released</b>
+  <li><b>7 November 2015 -- 2015.11-rc1 released</b>
 
     <p>We have a new release candidate! Lots of changes all over the
     tree, see
     the <a href="http://git.buildroot.net/buildroot/plain/CHANGES?id=2015.11-rc1">CHANGES</a>
-    file for details.</p>
+    file for details. See also
+    the <a href="http://lists.busybox.net/pipermail/buildroot/2015-November/144026.html">announcement
+    e-mail</a>.</p>
 
     <p>Head to the <a href="/downloads/">downloads page</a> to pick up the
     <a href="/downloads/buildroot-2015.11-rc1.tar.bz2">2015.11-rc1