Provide a GitHub Actions alternative entry

[tisonkun]

This follows how semantic-pull-requests probot app recommends its GitHub Actions alternative.

The core logic of tisonkun/actions-dco is a fork of this repo and already verified on multiple repos:

• nmstate/nmpolicy
• milvus-io/milvus-operator
• Seagate/cortx-manager

I propose to setup a friend link on this repo. What do you think?

[vercel[bot]]

@tisonkun is attempting to deploy a commit to the DCO App Team on Vercel.

A member of the Team first needs to authorize it.

[tisonkun]

Closed as no response. If you want to add such a link, you can still make use of this patch.