Expand the content of the README.md file

Reviewed MR!2, the file is not updated as per readme.md file template.

1. ## Introduction should replace by file name.
2. After introduction, table of content should be come.

Thanks for the feedback @Nupur Badola, I have updated the MR.

Reviewed MR!5, There is an error.
Two lines prior to ##/### headings

Updated the spacing, please review.

Thanks everyone!

Automatically closed - issue fixed for 2 weeks with no activity.