Assignment callout made more clear

1-Introduction/1-intro-to-ML/README.md

1-Introduction/2-history-of-ML/README.md

1-Introduction/3-fairness/README.md

2-Regression/1-Tools/README.md

2-Regression/2-Data/README.md

2-Regression/3-Linear/README.md

2-Regression/4-Logistic/README.md

3-Web-App/1-Web-App/README.md

4-Classification/1-Data/README.md

4-Classification/2-Discriminative/README.md

4-Classification/3-Generative/README.md

4-Classification/4-Applied/README.md

5-Clustering/1-Visualize/README.md

5-Clustering/2-K-Means/README.md

5-Clustering/2-K-Means/solution/notebook.ipynb

6-NLP/1-Introduction-to-NLP/README.md

6-NLP/2-Tasks/README.md

6-NLP/3-Translation-Sentiment/README.md

6-NLP/4-Hotel-Reviews-1/README.md

6-NLP/5-Hotel-Reviews-2/README.md