ML Tour from scratch

Roadmap:

1. [x] Perceptron from scratch
2. [x] Decision boundary with synthetic data
3. [x] Perceptron vs Adaline (GD)
4. [x] Perceptron vs Adaline vs MB-SGD (Adaline +) vs Shuffled vs non-shuffled
5. [x] KNN
6. [] L1 & L2
7. [] PCA
...