include missing

git-svn-id: svn://svn.openwrt.org/openwrt/trunk/openwrt@484 3c298f89-4303-0410-b956-a3cf2f4a3e73

docs/buildroot-documentation.html

@@ -428,7 +428,7 @@ foo-compile: bar-compile
 
 <pre>
      1  # $Id$
-     2  
+     2  include $(TOPDIR)/rules.mk
      3  PKG_NAME:=foo
      4  PKG_VERSION:=1.0
      5  PKG_RELEASE:=1