add a src-link example to feeds.conf.default

SVN-Revision: 18773

feeds.conf.default

@@ -5,3 +5,4 @@ src-svn luci http://svn.luci.subsignal.org/luci/branches/luci-0.9/contrib/packag
 #src-svn efl svn://svn.openwrt.org/openwrt/feeds/efl
 #src-svn desktop svn://svn.openwrt.org/openwrt/feeds/desktop
 #src-svn xfce svn://svn.openwrt.org/openwrt/feeds/xfce
+#src-link custom /usr/src/openwrt/custom-feed