Adding a linear regression model to ml section and Read me should be updated as ML is not mentioned.

[prathapnsvr]

I would like to add a linear regression model to the ML folder which also includes Gradient Descent to train the model. Is that ok? and readme should be updated as it doesn't include the ml section in it but a section is available is algorithms folder.

[prathapnsvr]

made a pull request #737 . Please verify and merge.

[apoorvyadav1111]

I would like to know what dependencies can be utilized to add ML algorithms. Can we use numpy arrays or do we need to go with for loops?