Using Developer Certificate of Origin (DCO) for code sign-off

[dennyglee]

As Delta Lake is part of the LF AI & Data, the recommended approach for code sign-off is a Developer Certificate of Origin (DCO). For more information, please refer to this draft proposal.

By definition, our CONTRIBUTING.md follows the DCO approach. Though, we'd like to recommend:

• Clarifying this similar to how Chef DCO (here is a blog on this topic)
• Enforcing DCO to ensure that contributions are submitted by the author to this project.

Please feel free to discuss if you have any concerns with this approach.

[rtyler]

Makes sense to me 👍

[rtyler]

DCO has been enabled on this repository now 🥳