The README.md file of the validator.js repository, at present, is loaded with huge chunks of information, most notably the extensive list of validators. The presence of the validators list is crucial in the README.md file but the importance of the other information cannot be overlooked as well.

The contribution guidelines can exist as a separate entity holding a good quantity of information. So, to make it more accessible, I have created a dedicated CONTRIBUTING.md file where I have shifted all the necessary information. Also, I have formatted the content slightly and added relevant links to better the user experience.

Checklist

• PR contains only changes related; no stray files, etc.
• README updated (where applicable)
• Tests written (where applicable)
• References provided in PR (where applicable)