feat: add k-nearest neighbor machine learning algo

[Cyntwikip]

Description

This is my implementation of the k-nearest neighbors machine learning algorithm.

Sample Usage:

clf = KNeighborsClassifier(n_neighbors=3, p=2, n_jobs=-1) # instantiate model
clf.fit(X_train, y_train) # train the model
score = clf.score(X_test, y_test) # does prediction and score evaluation in 1 line
print(f"Test Set Score: {score:.2%}")

Checklist:

• Code contain Problem statement, examples test cases.
• My code follows the style guidelines(Clean Code) of this project
• I have performed a self-review of my own code
• Explained Detailed approach of Solution
• I have commented on my code, particularly in hard-to-understand areas
• Performed Time complexity analysis of the algorithm used in code