feat: add linear regression machine learning algo through OLS method

[Cyntwikip]

Description

My implementation of the Linear Regression Machine Learning algorithm through Ordinary Least Squares (OLS) method.

Sample Usage:

ols = OLS()
ols.fit(x.reshape(-1,1), y)
ols.predict(x)

Checklist:

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