翻译 model_intro.md
翻译 model_intro.md

thinkjs/www.thinkjs.org,thinkjs/www.thinkjs.org,75team/www.thinkjs.org,75team/www.thinkjs.org,thinkjs/www.thinkjs.org,snadn/www.thinkjs.org,snadn/www.thinkjs.org,snadn/www.thinkjs.org,75team/www.thinkjs.org