Update region guidelines

[Nirvikalpa108]

Updating the rules on the region section for contributing company information as per #485

This is a modified version of the Contributing Guidelines.

This pull request adheres to the repository's Code of Conduct.

• I am an employee of the company mentioned and confirm all included details are correct
• This PR contains housekeeping only (URL edits, copy changes etc)
• You know your alphabet - company is listed in alphabetical order in the README
• The company directly hires employees. No bootcamps / freelance sites / etc
• The company hires remote employees, or positions are available to remote workers and are clearly illustrated as such
• A company profile is included - Required for new additions. (This can be a basic outline but at least something please)
• Remote status has details regarding how the culture includes remote employees, how the company integrated remote workers, etc
• Region details any restrictions to applicants based on geography
• How to apply details the best approach for new applications, page on site where open position are listed, and any other help available for job hunters

[dougaitken]

I'm liking this update so far, thanks for doing this Amina.

[nylen]

Thanks for the PR! Good to see us moving further towards organizing this data.