Follow up old PRs (#4008)

* Add "What I Wish I Knew When Learning Haskell"

Follow up #3173.

* Update free-programming-books-zh.md

Follow up #3330.

* added competitive programming link

Follow up #3398.

free-programming-books-zh.md

@@ -153,6 +153,7 @@
 * [极客学院](http://www.jikexueyuan.com)
 * [汇智网](http://www.hubwiz.com)
 * [计蒜客](http://www.jisuanke.com)
+* [黑马程序员](http://yun.itheima.com)
 
 
 ### 大数据
@@ -645,6 +646,7 @@
 * [Python之旅](http://funhacks.net/explore-python) - Ethan
 * [Python教程 - 廖雪峰的官方网站](http://www.liaoxuefeng.com/wiki/0014316089557264a6b348958f449949df42a6d3a2e542c000)
 * [Tornado 6.1 中文文档](http://www.osgeo.cn/tornado/) - (网络上其他的都是较旧版本的，Online)
+* [人生苦短，我用python](https://www.cnblogs.com/derek1184405959/p/8579428.html) - (内含丰富的笔记以及各类教程)
 * [像计算机科学家一样思考Python](https://www.ctolib.com/docs/sfile/think-python-2e/0.html) - Allen B. Downey、大胖哥(翻译)
 * [深入 Python 3](https://github.com/jiechic/diveintopython3)
 * [简明 Python 教程](https://bop.molun.net) - Swaroop C H、沈洁元(翻译)、漠伦(翻译)

free-programming-books.md

@@ -1428,6 +1428,7 @@ Kerridge (PDF) (email address *requested*, not required)
 * [Parallel and Concurrent Programming in Haskell](https://www.oreilly.com/library/view/parallel-and-concurrent/9781449335939/) -  Simon Marlow
 * [Real World Haskell](http://book.realworldhaskell.org)
 * [Speeding Through Haskell](http://www.sthaskell.com)
+* [What I Wish I Knew When Learning Haskell](http://dev.stephendiehl.com/hask/) - Stephen Diehl (PDF)
 * [Wise Man's Haskell](https://anchpop.github.io/wise_mans_haskell/) - Andre Popovitch
 * [Yet Another Haskell Tutorial](http://hal3.name/docs/daume02yaht.pdf) (PDF)
 

free-programming-playgrounds.md

@@ -163,6 +163,7 @@
 ### React
 
 * [CodeSandbox.io](https://codesandbox.io)
+* [jscomplete](https://jscomplete.com/playground)
 * [StackBlitz](https://stackblitz.com/fork/react)
 
 

problem-sets-competitive-programming.md

@@ -21,6 +21,7 @@
 * [Codewars](http://www.codewars.com)
 * [Codingame](https://www.codingame.com/start)
 * [Facebook Hackercup](https://www.facebook.com/hackercup)
+* [Google Code Jam](https://codingcompetitions.withgoogle.com/codejam)
 * [HackerEarth](https://www.hackerearth.com)
 * [Hackerrank](https://www.hackerrank.com)
 * [Internet Problem Solving Contest](http://ipsc.ksp.sk)