Added more courses for Data Science (#7792)

* Added more courses for Data Science

Grouped the courses by websites plus added 10 more to it

* Update free-courses-en.md

* Update free-courses-en.md

* sort

* move R resource

* Update courses/free-courses-en.md

* Update courses/free-courses-en.md

* Update courses/free-courses-en.md

* Update courses/free-courses-en.md

* Update courses/free-courses-en.md

* Update courses/free-courses-en.md

* Update courses/free-courses-en.md

* Update courses/free-courses-en.md

Co-authored-by: Eric Hellman <eric@hellman.net>

courses/free-courses-en.md

@@ -412,6 +412,7 @@
 ### Data Science
 
 * [Advanced Data Mining with Weka MOOC](https://www.cs.waikato.ac.nz/ml/weka/mooc/advanceddataminingwithweka/)
+* [An Introduction to Data Science](https://www.udemy.com/course/an-introduction-to-data-science/)
 * [Apache Airflow Tutorials](https://www.youtube.com/playlist?list=PLYizQ5FvN6pvIOcOd6dFZu3lQqc6zBGp2) - Tuan Vu (YouTube)
 * [Applied Data Science with Python](https://cognitiveclass.ai/learn/data-science-with-python) - CognitiveClass.ai
 * [CS250: Python for Data Science](https://learn.saylor.org/course/view.php?id=504) - Saylor Academy
@@ -430,7 +431,11 @@
 * [Datavis 2020](https://www.youtube.com/playlist?list=PL9yYRbwpkykuK6LSMLH3bAaPpXaDUXcLV) - Curran Kelleher
 * [IBM Data Science Professional Certificate](https://www.coursera.org/professional-certificates/ibm-data-science) (Coursera)
 * [Intro to Data Analysis](https://www.udacity.com/course/intro-to-data-analysis--ud170) - Udacity
+* [Intro to Data Science](https://www.udacity.com/course/intro-to-data-science--ud359) - Udacity
+* [Introduction to Data Science](https://alison.com/course/introduction-to-data-science-revised) - Alison
+* [Introduction to Data Science](https://www.simplilearn.com/data-science-free-course-for-beginners-skillup) - SkillUp by Simplilearn
 * [Introduction to Data Science in Python](https://www.coursera.org/learn/python-data-analysis) - Christopher Brooks (Coursera)
+* [Learn Data Science Tutorial - Full Course for Beginners](https://www.youtube.com/watch?v=ua-CiDNNj30) - Barton Poulson (FreeCodeCamp.org)
 * [MIT's Introduction to Computational Thinking and Data Science](https://ocw.mit.edu/courses/electrical-engineering-and-computer-science/6-0002-introduction-to-computational-thinking-and-data-science-fall-2016/) - Eric Grimson, John Guttag, Ana Bell (MIT OpenCourseWare)
 * [More Data Mining with Weka MOOC](https://www.cs.waikato.ac.nz/ml/weka/mooc/moredataminingwithweka/)
 * [NICO 101 - Introduction to Programming for Big Data](https://github.com/amarallab/Amaral_Lab_Intro_to_Data_Science) - Luis Amaral, Helio Tejedor, Luiz Alves