Add credits

1-Introduction/01-defining-data-science/README.md

@@ -156,3 +156,7 @@ Visit [`notebook.ipynb`](notebook.ipynb) to read through the code. You can also
 
 * **Task 1**: Modify the code above to find out related concepts for the fields of **Big Data** and **Machine Learning**
 * **Task 2**: [Think About Data Science Scenarios](assignment.md)
+
+## Credits
+
+This lesson has been authored with ♥️ by [Dmitry Soshnikov](http://soshnikov.com)

1-Introduction/04-stats-and-probability/README.md

@@ -251,3 +251,6 @@ Probability and statistics is such a broad topic that it deserves its own course
 
 [Small Diabetes Study](assignment.md)
 
+## Credits
+
+This lesson has been authored with ♥️ by [Dmitry Soshnikov](http://soshnikov.com)

2-Working-With-Data/07-python/README.md

@@ -273,3 +273,7 @@ Whether you already have structured or unstructured data, using Python you can p
 ## Assignment
 
 [Perform more detailed data study for the challenges above](assignment.md)
+
+## Credits
+
+This lesson has been authored with ♥️ by [Dmitry Soshnikov](http://soshnikov.com)