Added Intro to AI and Intro to Machine Learning courses

Author: The-Atul-Sharma

extras/courses.md

@@ -86,8 +86,16 @@
 
 ### Artificial Intelligence
 
+Courses | Duration | Effort
+:-- | :--: | :--:
+[Intro to Artificial Intelligence (Udacity)](https://www.udacity.com/course/intro-to-artificial-intelligence--cs271)| 16 weeks | 6-10 hours/week
+
 ### Machine Learning
 
+Courses | Duration | Effort
+:-- | :--: | :--:
+[Intro to Machine Learning (Udacity)](https://www.udacity.com/course/intro-to-machine-learning--ud120)| 10 weeks | 6-10 hours/week
+
 ### Natural Language Processing
 
 ### Big Data