r.d.n: improve description of what this is about

Signed-off-by: Holger Levsen <holger@layer-acht.org>

hosts/osuosl5-amd64/var/www/html/index.html

@@ -136,6 +136,7 @@
 	<p>
 	To be a bit more verbose:
 	<br/>
+	for any distributed package,
 	rebuilderd calls debrebuild that calls debootsnap, mmdebstrap and sbuild
 	that finally builds that package in a user namespace.
 	<br/>