Update README.md

Author: tg123

README.md

@@ -1,15 +1,18 @@
-Leetcode
-========
-
-After 151 Done(Jul 20 2014)
---------------------------
+#Leetcode solutions
 
 [Github Page](http://leetcode.tgic.me/)
 
 Please [Donate leetcode](https://oj.leetcode.com/donate/)
 
-TODO
-----
- * Impove code readability
- * Write down thinkings how problems were solved
 
+## Milestone
+
+ * 151 AC _Jul 20 2014_
+ * 151 Detailed solving thought  _Aug 31 2014_
+
+
+## TODO
+ 
+ * Evaluate the Time and Space complexity of each solution
+ * Proof the code's correctness if needed
+ * Find better solutions