add jquery resource

Author: frankdevhub

_includes/head.html

@@ -24,6 +24,9 @@
 	<!--<script type="text/javascript" src="https://cdn.rawgit.com/christian-fei/Simple-Jekyll-Search/master/dest/simple-jekyll-search.min.js"></script>-->
 	<script type="text/javascript" src="/js/simple-jekyll-search.min.js"></script>
 	<!-- search end -->	
+	
+	<!--jquery-->
+	<script type="text/javascript" src="/js/jquery-3.1.1.min.js"></script>
 
 {% if site.baidu_tongji_id %}
     <script>