Add courses (React, Data structures and Algorithms) (#6303)

* adds new React course

* adds a new data structures and algorithms tutorial

* remove course duplicate

courses/free-courses-en.md

@@ -104,6 +104,7 @@
 * [Data Structures and Algorithms](https://www.youtube.com/playlist?list=PLdo5W4Nhv31bbKJzrsKfMpo_grxuLl8LU) - Jenny's lectures CS/IT NET&JRF
 * [Data Structures and Algorithms for Beginners](https://www.youtube.com/watch?v=BBpAmxU_NQo) - Programming with Mosh
 * [Data Structures and Algorithms Specialization](https://www.coursera.org/specializations/data-structures-algorithms) - UC San Diego, HSE University
+* [Data Structures and Algorithms Tutorial](https://www.tutorialspoint.com/data_structures_algorithms/) - Tutorials Point
 * [Data Structures Easy to Advanced Course - Full Tutorial from a Google Engineer](https://www.youtube.com/watch?v=RBSGKlAvoiM) - William Fiset - (freeCodeCamp)
 * [IIT Bombay Foundation of Data Structures (CS213.1x)](https://courses.edx.org/courses/course-v1:IITBombayX+CS213.1x+1T2017/course/)
 * [Intro to Data Structures and Algorithms](https://www.udacity.com/course/data-structures-and-algorithms-in-python--ud513) - Brynn Claypoole, Horatio Thomas (Udacity)