Update Readme.md

[ariella879]

IMPORTANT: Please do not create a Pull Request without creating an issue first.

Any change needs to be discussed before proceeding.

Description

I have fixed all the grammar mistakes including the missing articles and etc.

Please link to the issue here: #450

Types of changes

What types of changes does your code introduce? Put an x in all the boxes that apply:

• Bug fix (change which fixes an issue with the algorithm)

• New Algorithm (non-breaking change which adds functionality)

• [X ] Documentation

Checklist:

Go over all the following points, and put an x in all the boxes that apply.

If you're unsure about any of these, don't hesitate to ask. We're here to help!

• My code follows the code style of this project.

• [ X] My change requires a change to the documentation.

• [X ] I have updated the documentation accordingly.

• [X ] I have read the CONTRIBUTING document.