message: Add a new useful resource
diff: * [CodeChef](https://www.codechef.com/)
  * [Codeforces](https://codeforces.com/)
  * [Hackerearth](https://www.hackerearth.com/challenges/)
  +* [freeCodeCamp](https://www.freecodecamp.org/learn/)
  [GeeksForGeeks](https://www.geeksforgeeks.org/) - Best place to find detailed notes on theoretical subjects including Database Management System, Data Structures, Data Algorithms, Object Oriented Programming, Operating Systems and many more.An all rounder website for placement preparation having company wise coding questions and MCQs.
  