Update README.md

https://github.com/settings/admin · https://github.com/settings/admin · commit a30f53aaaaaa · 2013-01-10T15:14:48.000+08:00
diff --git a/README.md b/README.md
@@ -3,3 +3,7 @@
 *强调*
 **加重强调**
 *** 特别强调 ***
+
+- [] list1
+- [] list2
+- [x] list3
