Added a new Data Science Course named Data Science Methodology in English Course list (#7761)

* Added a new course in Data Science

* Added a new Data Science resource

* Bad Link Issue Resolved

Resolved the bad link at updated the working one
Hope my PR gets merged now!

courses/free-courses-en.md

@@ -347,6 +347,7 @@
 * [Data science for beginners](https://microsoft.github.io/Data-Science-For-Beginners) - Microsoft
 * [Data Science Fundamentals](https://cognitiveclass.ai/learn/data-science) - CognitiveClass.ai
 * [Data Science interview questions](https://www.youtube.com/playlist?list=PLZoTAELRMXVPkl7oRvzyNnyj1HS4wt2K-) - Krish Naik
+* [Data Science Methodology](https://cognitiveclass.ai/courses/data-science-methodology-2) - CognitiveClass.ai
 * [Data Visualization](https://www.kaggle.com/learn/data-visualization) - Alexis Cook (Kaggle)
 * [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)