Update problem-sets-competitive-programming.md (#4444)

* Update problem-sets-competitive-programming.md

* Update problem-sets-competitive-programming.md

problem-sets-competitive-programming.md

@@ -52,6 +52,7 @@
 ### Data science
 
 * [AIcrowd](https://www.aicrowd.com)
+* [CodaLab](https://competitions.codalab.org)
 * [DrivenData](https://www.drivendata.org)
 * [Kaggle](https://www.kaggle.com)