Document Tearing Everything Down on DigitalOcean

[hmharshit]

Although the documentation contains tearing down for AWS and Microsoft Azure. I will like to add the specific steps needs to completely tear down for DigitalOcean.

If moderators agree, I can send a Pull Request for the same enhancement in the documentation.

Let me know If I can send a PR for the same.

[consideRatio]

This is relevant documentation, for anyone wanting to open a PR about that, please go ahead!