fix broken link to CONTRIBUTING.md
fix broken link to CONTRIBUTING.md

waruqi/xmake,waruqi/xmake,tboox/xmake,waruqi/xmake,tboox/xmake,tboox/xmake,waruqi/xmake,waruqi/xmake,waruqi/xmake,tboox/xmake,tboox/xmake,tboox/xmake,tboox/xmake,waruqi/xmake