Rename packages organization from `com.velocidi` to `com.kevel`

[beatriz]

This changes the packages from the com.velocidi to com.kevel organization to reflect the organizational change. For now, it doesn't touch the publishing organization as I still need to figure out some things for that.

After making the change I wondered if we'd want to use adzerk instead to be consistent with the GitHub organization name, what do you think?

I am leaving this with the do not merge label for now, as I know we'd like to get a Pekko update without this impacting its release. I will also try to figure out the publish organization to try to get it all at once.

Does this change relate to existing issues or pull requests?

No.

Does this change require an update to the documentation?

Updated the README docs as well.

How has this been tested?

Relying on CI to validate everything keeps working.