添加机器学习经典博客url

朱伟 · 朱伟 · commit 603790a54872 · 2018-03-10T14:05:36.000+08:00
diff --git a/README.md b/README.md
@@ -21,4 +21,5 @@ http://logos.name/archives/236；
 4.9 http://blog.csdn.net/han_xiaoyang/article/category/5877239/2; --寒小阳
 4.10 http://www.cnblogs.com/LeftNotEasy/tag/machine%20learning/; --Wangda Tan
 4.11 http://www.cnblogs.com/tornadomeet/category/361811.html; --tornadomeet 
-4.12 http://studyai.site/tags/%E6%9C%BA%E5%99%A8%E5%AD%A6%E4%B9%A0/page/2/; --studyAI
+4.12 http://studyai.site/tags/%E6%9C%BA%E5%99%A8%E5%AD%A6%E4%B9%A0/page/2/; --studyAI
+4.13 http://freemind.pluskid.org/archive/; --Free Mind 
