Merge pull request ossu#288 from razat249/patch-2

Added intro to cs udacity in extras section

Author: ericdouglas

extras/courses.md

@@ -39,6 +39,7 @@
 
 Courses | Duration | Effort
 :-- | :--: | :--:
+[Introduction to Computer Science (Udacity)](https://www.udacity.com/course/intro-to-computer-science--cs101)| 7 weeks | 10-20 hours/week
 [Introduction to Computer Science](https://www.edx.org/course/introduction-computer-science-harvardx-cs50x#!)| 12 weeks | 10-20 hours/week
 [An Introduction to Interactive Programming in Python (Part 1)](https://www.coursera.org/learn/interactive-python-1)| 5 weeks | -
 [An Introduction to Interactive Programming in Python (Part 2)](https://www.coursera.org/learn/interactive-python-2)| - | -