参看网址：
http://ghbtns.com/
譬如fecshop显示小图标的代码：
<div style="margin-top:5px">
<iframe src="https://ghbtns.com/github-btn.html?user=fecshop&repo=yii2_fecshop&type=watch&count=true&v=2" frameborder="0" scrolling="0" width="105px" height="21px"></iframe>
<iframe src="https://ghbtns.com/github-btn.html?user=fecshop&repo=yii2_fecshop&type=star&count=true" frameborder="0" scrolling="0" width="102px" height="21px"></iframe>
<iframe src="https://ghbtns.com/github-btn.html?user=fecshop&repo=yii2_fecshop&type=fork&count=true" frameborder="0" scrolling="0" width="110px" height="21px"></iframe>
</div>