Update Readme (Cloud-CV#4781)

* Update README to correct build status link and improve coverage badge formatting

* Remove .all-contributorsrc file and update README to reflect current contributors

* Update README to include a non-exhaustive list of past contributors

* Update README to format contributor links for better readability

* Update README to add target="_blank" attribute to external links for improved accessibility

* Update README to ensure all contributor links open in a new tab for improved user experience

* Update README to convert external links to HTML anchor tags for improved accessibility and consistency

Author: RishabhJain2018