Add Tinc Source Code to OpenWrt Source code

Hello Everyone,
Am trying to add Tinc source code to Openwrt source code as a package but i think am doing something wrong...
so far i added new folder (called tinc) to package directory in Openwrt source code project.
inside i added Makefile according to this guide:
and the tinc tar.gz download from there site.
but now am don't really know where should I mention about the new added package.
is in the include folder ?