Hi! This PR adds a link to [Cloudsmith](https://cloudsmith.io), which is a package management service SaaS. It's commercial, but it is completely free for open-source and it has generous free tiers otherwise. It has first-class support for Docker (and many other package formats, such as Helm), plus org/teams management, granular access controls, private repositories, repository-specific entitlements, a worldwide content distribution network, webhooks, access logs, etc. Thank you. :-)
Full disclosure: I work at Cloudsmith. \o/
