Adding Linear Discriminant Analysis (#1592)

* Adding new file to the machine_learning directory

* Adding initial documentation

* importing modules

* Adding Normal_gen function

* Adding Y_gen function

* Adding mean_calc function

* Adding prob_calc function

* Adding var_calc function

* Adding predict function

* Adding accuracy function

* Adding main function

* Renaming LDA file

* Adding requested changes

* Renaming some of functions

* Refactoring str.format() statements to f-string

* Removing unnecessary list objects inside two functions

* changing code style in some lines

* Fixing y_generator function

* Refactoring 'predict_y_values' function by using list comprehensions

* Changing code style in import statements

* Refactoring CLI code block

* fixup! Format Python code with psf/black push

* No lines longer than 88 characters