Update README Sections and fix grammar

[eeshaanSA]

Updated the Readme in the following ways:

1. Prased major sections of the readme and used correct english and grammar.
2. Updated the Project Setup to better reflect current errors and updated some commands.
3. Updated the Readme, assisting contributors to tackle the variables.sass error.

Description

Related Issue

Motivation and Context

COntributors were facing a lot of errors when setting up the project including me, so updated the README acordingly.

Screenshots (In case of UI changes):

Types of changes

• [ ] Bug fix (non-breaking change which fixes an issue)
• [ ] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• [ ] My code follows the code style of this project.
• [ ] My change requires a change to the documentation.
• [ ] I have updated the documentation accordingly.
• [ ] All new and existing tests have passed and it does not give any unexpected error for the same.