Fix the link to the contribution docs

[yunussaha]

Hi There

I was trying to read the contribution docs, so i can build and test the project locally. but i found that the link to the contribution docs is not working. giving 404 due to the file incorrectly named as CONTRIBUTING.ms. Please someone needs to fix it by renaming it to CONTRIBUTING.md.

It will help me and others read the docs with proper markdown format.

I hope a contributor fixes this or let me fix it by making a pull request.

Thanks for your attention.

[Christymulligan7]

Christy

[Christymulligan7]

Fixed