Create CONTRIBUTING.md (Issue #482)

[owengaspard]

I have added a small contributing guide for anyone looking to contribute to this project. This refers to issue #482.

• This PR contains housekeeping only (URL edits, copy changes etc) - if this is checked, delete other lines that don't apply.

[Ki-er]

A standard contributing document already exists, #482 referes to a technical contributing document to help with the site (https://remoteintech.company/).

[dougaitken]

Yes @owengaspard, I appreciate your enthusiasm but @KieranRobson is correct, as mentioned in the Issue content and my comment, it is based around how the site is built rather than contributing to the list.

Also, companies remains lowercase and that section about ⚠️ will remain on the main page until I fully clean up the list.

[dougaitken]

Hi @owengaspard

If you're still wanting to make a technical contributing document, please do open a new Pull Request with the details. Thanks.